Thanks to reading this Wikipedia article I’ve realised I can claim to know 2 versions of English, or at least 2 dialects, I hadn’t realised how many differences there are. There may be some more recent words which are missing as I left N. America on 1996!
I removed around 20% of the Wikipedia list, i.e., those words which I never heard in common usage.
I’m sure the following is not exhaustive
providing opportunities in education or work based on (e.g.) race or gender (UK: positive discrimination)
fixed-wing aircraft. Alteration of UK aeroplane, probably influenced by aircraft
(verb) (UK and US: sort alphabetically)
the herb also known as rocket or garden rocket. Borrowed from southern Italian dialect in the early 1960s (”Ask Italian greengrocers for arugula, rucola or ruccoli; ask other markets for rouquette, rocket salad or, simply, rocket.” — The New York Times, May 24, 1960, in OED).
pushable vehicle for transporting babies, also called stroller, buggy or regionally baby coach (UK: perambulator (very old-fashioned or formal), pram, or, for the type that an older baby sits rather than lies in, pushchair or buggy)
a baseball stadium; although used as well to mean range of approximation or accuracy (”in the ballpark”; “a ballpark figure”) *
(trademark) bandage for minor wounds, (UK: Elastoplast (trademark), plaster [DM]); also, a makeshift solution
front part of the hair cut to hang over the forehead (UK: a fringe)
a hotel porter
(on a horse) (UK: blinkers)
a walkway usually made of planking, typically along a beach (as that of Atlantic City) (UK: promenade)
hair grip, Kirby grip
(slang) a piece of nasal mucus (UK: bogey)
a large portable stereo, syn. with ghettoblaster, which is also American in origin but is common in the UK.
(also the boonies) rough country; a very rural location or town; backwoods; the “sticks”. Sometimes refers to rough, poor neighborhoods in a city. From Tagalog.
a box for keeping bread (UK: usually bread bin)
to cook food with high heat with the heat applied directly to the food from above (UK: grill) [DM]. Apparently first used by Chaucer.
a type of residential building found in New York City and other large cities
a friend; also used as a term of address (UK similar: mate)
junior restaurant worker assisting waiting staff, table clearer, water pourer etc. (UK: busser; runner)
a train car attached usually to the rear mainly for the crew’s use (UK: guard’s van’ or brake van’); also (colloquial) the buttocks
(of a vehicle) to travel fast and out of control, usually swerving or cornering (UK: career)
a four wheeled wire frame used to carry shopping (UK: trolley)
cell phone *
(short for cellular telephone) a portable telephone; UK: mobile phone, often abbreviated to mobile
(trademark, sometimes used generically) a lip balm – trademark Lypsyl is common (UK: Lip Balm *)
a popular board game (UK: draughts)
in a store or shop (UK: credit account)
the type of bank account used for drawing checks; distinguished from savings account. (UK: current account or cheque account)
coriander leaf, while in the US, coriander refers only to the seed.
(slang) temper tantrum.
informal meal cooked and eaten outdoors, a cross between a picnic and a barbecue or a cooking competition taking place outdoors
female student at a coeducational college (e.g., “He saw the party as an opportunity to meet co-eds.”); any group of people with members from both genders (e.g. “My soccer team is co-ed.”)
fictional disease, a term used by children (UK: germs, lurgy); also a term for lice
party where costumes are worn (UK: fancy-dress party)
spun sugar often sold at fairs (UK: candy floss)
a one-piece outer protective garment (UK: overall, boiler suit)
(informal) a creature; an animal (as a horse in the South or a bull in the North); often used jocularly (as in “congresscritter”, a congressperson); sometimes a term of endearment
risky and uncertain venture; from craps, a dice game
An absorbent undergarment (UK: nappy)
a 10-cent coin. Derived from the French word disme (the original spelling), meaning a tenth part or tithe, and ultimately from the Latin decima. Five-and-dime, dime store, a store selling cheap merchandise; a dime a dozen, so abundant as to be worth little; on a dime, (slang) ten dollars, in a small space (”turn on a dime”) or immediately (”stop on a dime”); nickel-and-dime, originally an adjective meaning “involving small amounts of money” and then “insignificant”, also a verb meaning “to rip-off by many seemingly insignificant charges”. (The nickel [DM] is the 5-cent coin.) In Britain, the old sixpence, a small coin of a comparable size and value, was formerly used in similar expressions before a decimal currency was introduced in the 1971.
a method of payment by bank transfer, similar to European giro, almost exclusively used for deposits of pay checks or government benefits
to confuse or disconcert; upset; frustrate (UK and US: discompose)
a cloth for washing dishes (UK and US: dishcloth)
a liquid soap used for washing dishes (UK “washing-up liquid”)
a towel for drying dishes (UK: tea towel)
device for rinsing the vagina or anus; also douchebag* is used as an insult
(noun, adv., adj.) (in, to, toward, or related to) either the lower section or the business center of a city or town—(used in UK but more common expression would be city centre)
driver license, driver’s license
(UK: driving licence)
a pharmacy, or a store selling candy, magazines, etc. along with medicines (UK approx.: chemist or “corner shop” [DM])
preference of one thing over another derived from a contraction of “I would rather” or “I’d rather” (e.g., “if I had my druthers, I’d…”)
gypsum board, plasterboard, or any process that builds interior walls without the use of water (UK: plasterboard)
A male or a farm hand at a horse ranch. Americans often use this as the combined equivalent of the British usage of “mate” and “bloke”, or, even closer, as the equivalent of Caribbean “man/mon”. Dude has become more understood in the UK due to television, films, music, etc.
(trademark: might be becoming genericized) large trash receptacle (UK approx.: skip [DM]); to dumpster-dive, to rummage through a Dumpster
a boring, studious or socially inept person (a nerd, a geek or a “drip” an old-fashioned mild pejorative for someone exceptionally eccentric or lacking in social skills)
the plant Solanum melongena (UK: aubergine); “eggplant” is common in the Commonwealth outside the United Kingdom.
brake in motor vehicle operated by a lever used to keep it stationary. Also referred to as an “E-brake”. (UK: handbrake)
(UK: “muffin“, “hot muffin“) (for more, see article)
(UK: rubber [DM])
As in expiration date (UK: expiry)
A type of limited-access road (UK “motorway“)
water outlet (UK and US: tap [DM])
a publicist or press agent; sometimes also an alternate spelling of flak “negative commentary”, which is used in the UK. Although flack “press agent” was first recorded just one year after flak “Flugabwehrkanone”, the two are likely unrelated.
portable battery-powered electric lamp (UK: torch)
(see article) (UK motorway)
a first-year student in college or high school (fresher in UK)
French fries (or fries)
pieces of potato that have been deep-fried. Originates from Belgian style of cooking potatoes (UK chips: e.g., fish and chips or pie and chips)
A confection applied to cakes (US and UK: icing)
garbage can; waste basket
(UK: rubbish bin or simply bin, as in “Put the rubbish in the bin.”)
(esp. in the past also spelled gasolene; abbreviated gas) (UK: petrol)
as an interjection, a euphemism for “Jesus”; as an adjective, denotes something characterized by or meant to cause excitement or sensation (”gee-whiz technology”; “a gee-whiz attitude”)
the very beginning (of something) 
(UK: green fingers)
a con artist, transient swindler, or professional gambler (UK: con man); also grift can mean an act of thievery or trickery
Archaic in most of the UK except Yorkshire where it is widely used.
a bruise on one’s skin resulting from kissing or sucking; (UK: love bite * )
The word “whore“, synonymous with tramp (harlot) or slut and often used as an insult. The spelling is associated with African-American English, though it does no more than reflect a non-Rhotic pronunciation of the standard word, similar to what can be heard in Boston (”haw” or “ho-wuh”) or Australia.
tramp (BrE); subculture of wandering homeless people, particularly those who make a habit of hopping freight trains. Becoming more popular in the UK
engine compartment cover of front-engine automobile (UK: bonnet)
to play truant from school; to cut class (UK also: skive, bunk off or playing wag or wagging off or mooching)
simply “riding” or horse riding in the UK
(short for how do you do) casual greeting that originated in the Southern States. (UK How do?)
jack off, jerk off *
(slang) to masturbate; UK usage would be “to wank”. If used as a disparaging noun, as in “that guy is such a jackoff [or jerkoff]“, the UK equivalent would be “that bloke is such a wanker (or a “tosser”)”. In this sense, sometimes written “jagoff”. (It is generally not considered as vulgar or insulting as “wanker” is, however.) Can also mean to delay, stymie, thwart, or cause confusion, sometimes with the intent to defraud (”I’ve waited an hour to be served; they’re jerking me off,”; “They say I never returned the car- I left it in the lot. I’m getting jerked off here.”) In the latter sense, may also be “jerked around”.
(UK: pneumatic drill)
See John Doe.
minced oath for “Jesus”, sometimes spelled geez
(trademark) gelatin dessert (UK: jelly [DM])
(slang) a toilet; also, the client of a prostitute
(slang) penis ( UK : “willy” )
unnamed defendant or victim (as in a lawsuit), or a person whose identity is unknown or is intended to be anonymous; also, an average man ; compare John Q. Public (UK equivalent is Joe Bloggs, or John Smith). The female equivalent is Jane Doe, or less frequently “Jane Roe” as in Roe v. Wade. Also Baby Doe.
a red, black-spotted beetle (UK: ladybird)
a public place to wash laundry (UK: laundrette)
a restricted license for a person learning to drive, who has not yet passed the necessary driver’s test (rules vary from state to state); also called driver’s permit (UK: provisional driving licence)
left field *
a source of unexpected or illogical questions, ideas, etc. (”that proposal came out of left field”); for the baseball sense see left fielder; see English language idioms derived from baseball (now becoming more common in the UK)
license plate, license tag
vehicle registration plate (UK: number plate)
see mail carrier
(UK: post box, letter box, pillar box)
mathematics (UK: maths).
(Miranda warning) the warning (usually “You have the right to remain silent. If you give up that right, anything you say can and will be used against you in a court of law.” etc.) given to criminal suspects when arrested; (Miranda rights) the right of a criminal suspect when arrested, as established in the United States Supreme Court case Miranda v. Arizona; hence mirandize, to recite the Miranda warning to (a criminal suspect). In the UK this is referred to as “reading rights” or “cautioned as to his rights” (not to be confused with a police caution).
a type of haircut (UK: mohican)
mama, mamma, momma
mother (UK often: mum[my], mam, ma)
single-family operated small business (”a mom-and-pop store”) (UK: family business)
mono / mononucleosis
(UK: Glandular fever)
(UK & US: undertaker, funeral director)
law enforcement narcotics agent; but ‘to narc on’ someone is to inform on them to an authority figure, used also as a noun labeling a person who does such. Also ‘Grass’ (UK and New Zealand) or ‘Dobber’ (Australia and most parts of the UK, except central Scotland where ‘dobber’ generally means ‘penis’).
encompassed by bedside table
of clothes, etc. (UK: off-the-peg)
irritable, crotchety, cranky, troublemaking (from ordinary)
temporary suspension of operation (”a power outage“, UK: powercut); the amount of something lost in storage or transportation [DM]
(UK: dummy [DM], comforter [DM])
(UK: tights, a term used for similar non-sheer garments in the U.S.; “pantyhose” refers only to sheer or semi-sheer nylon-based tights)
a regular series of newspaper deliveries (UK: paper round)
a roll of absorbent perforated paper used to clean around the house (UK: kitchen roll)
a usually outside area for the parking of automotive vehicles (UK: car park)
punctuation mark at the end of a sentence (UK: full-stop)
A trademarked brand of frozen juice, or flavored ice on a stick. The term is widely used to describe all such confections without regard to brand. (UK: ice lolly)
(UK: direct debit (variable amount)/standing order (fixed amount))
(UK: bank holiday, although public holiday is also used, more formally, when referring to New Year’s Day, Good Friday, Christmas Day and Boxing Day). See Federal holiday
short for “radical”, different or interesting, exceptional; synonym for cool
The metaphorical raincheck is used in the US to indicate that the person “taking the raincheck” regretfully cannot accept the current invitation but would like to be invited to a future event. Stores may “give a raincheck” when they have run out of an advertised item; this is usually a coupon to purchase the item later at the advertised price. In the UK the person “taking the raincheck” may attend an event, but is warning the host that there is a possibility that they may not be able to make it. Both usages are becoming more common in UK English, particularly amongst office workers.
member of the National Association of Realtors; as a genericized trademark, any real estate broker or real estate agent (UK: estate agent)
a toilet, particularly a public one.
RV (recreational vehicle)
see article for usage of the terms RV, motor home, and the British camper [DM] and caravan [DM]
(Saran is a trademark) plastic wrap (UK: cling film)
(trademark) sticky tape (UK: Sellotape [trademark])
shopping bag : (UK: carry bag)
A lawyer or accountant of dubious ethical standards. This phrase commonly indicates a person with no ethical restraints. (From German Scheister)
usually paved path for pedestrian traffic, often constructed of concrete or less usually of stone (UK: pavement [DM], footpath [DM])
(UK: skimmed milk)
(usually pl.) a form of footwear, also called tennis shoe or “gym shoe”—see regional vocabularies of American English (UK: trainer, plimsoll, regional dap,pump, [DM])
(colloqual Past Tense and Past Participle) form of “Sneak” ) (US standard and UK: Sneaked)
used in the UK but the sport is also known as “Football” or fully as association football
(UK: soft drink [without CO2 e.g. orange juice], or fizzy/carbonated drink [with CO2 e.g. Coca-Cola])
a second-year college or high school student (Trinity College Dublin has sophister in this sense); (adj.) the second in a series (as in, an athlete’s “sophomore season”, a band’s “sophomore album”) From the Greek: Sophos – Wise; and Moros – Fool, Moron (UK: undergraduate has this extended sense)
(UK: speciality, though specialty is used in law and medicine)
automobile with extended rear cargo area (UK: estate (car))
(car with) manual transmission, as opposed to an automatic (UK: gear stick or gear lever for the stick; manual for the car)
a sore throat caused by Streptococcus
stool pigeon, stoolie
police informer (UK: grass) (From the use of captive birds as hunting decoys)
A small porch, platform, or staircase leading to the entrance of a house or building. Chiefly Northeastern U.S.
vehicle on rails for passenger transportation [DM] usually within a city; also called trolley [DM] or trolley car if electrically powered by means of a trolley (UK: tram)
vehicle for baby transportation featuring the child in a sitting position, usually facing forward (UK: pushchair, buggy [DM])
A phrase expressing distaste or disapproval. Slowly entering British slang.
Sport-Utility Vehicle. Often referred to as a 4×4 (”four by four”) in the UK; in the US “4×4″ usually refers to a four wheel drive pickup truck
a knitted jacket or jersey (UK: jumper or wooly jumper)
(UK: track bottoms, tracksuit bottoms. Colloqially trackie bottoms or trackies)
(UK: takeaway; Scotland & US also: carry-out)
(see article) (UK: compare autocue)
Through. An abbreviation mostly used in the fast food industry, as in Drive Thru. Also used in traffic signs (”Thru Traffic Keep Left”; i.e., traffic that is continuing through an interchange rather than exiting should keep to the left) and occasionally road names (”New York State Thruway”) and sometimes in newspaper headlines. Absolutely not considered acceptable spelling in other contexts. Seen in the UK at McDonalds, Burger King etc.
short nail or pin with a large, rounded metal head (UK: drawing pin)
track and field meeting * (track meet)
(UK usually athletics meeting [DM]); see also track [DM]
(UK: dustbin, rubbish bin)
storage space usually over rear wheels of an automobile (excepting some) (UK: boot)
literally, worth 25 cents or a quarter (a bit is an eighth of a dollar); figuratively, worth very little, insignificant (informal). In UK the phrase “two bob“‘ exists although this far more common in London and the south-east. Likewise mickey mouse.
two cents, two cents’ worth
an opinion, a piece of one’s mind (as in, “I’m gonna go down there and give him my two cents”) – (UK similar: two pence, two penneth, two penn’orth or tuppence worth)
an upper undergarment with no collar, and with short or no sleeves, worn next to the skin under a shirt (UK: singlet, vest [DM], semmit in Scotland and Northern Ireland )
relating to goods targeted at high-income consumers (UK: upmarket)
(noun, adj., adv.) (in, to, toward, or related to) either the upper section or the residential district of a city; e.g., in Manhattan, New York City the term refers to the northern end of Manhattan, generally speaking, north of 59th Street; see also Uptown, Minneapolis; Uptown, Chicago; Uptown New Orleans; compare downtown. Often has implications of being a desirable or upscale neighborhood. However, in Butte, Montana and Charlotte, North Carolina, “Uptown” refers to what would be called “downtown” in most other cities.
an individual’s earned time off from work: usually 1 to 4 weeks (UK: holiday)
varmint or varmit
(from vermin) pest which raids farms, rather than infesting them
(UK: flannel, UK often & US less frequently facecloth; US less frequently also washrag)
synonym for trash can, especially one intended for light waste (UK: dustbin; wastepaper basket is an interior object for waste from each room.)
the front window of an automobile (UK: windscreen)
a mobster; also smartass (e.g., “hey, wiseguy…”) (UK: a “know-it-all”)
a witty, often caustic remark; something supposed to cause surprise or shock
(for Zone Improvement Plan) the postal code used by the United States Postal Service composed of 5 digits as in 90210, sometimes a suffix of 4 digits after a hyphen is used. (UK equivalent: postcode or post code or rarely postal code)
(UK usually zip [DM])
the plant Cucurbita pepo, also zucchini squash. (UK: courgette)