The subject of American English vs. British English is an ornery, troublesome one, and regularly appears in our blog posts. I’m particularly embroiled in this endless debate because I, an Englishman, have an American girlfriend. Now, ladies, please don’t cry. I know what’ll cheer you up: some comparative etymology. Never fails.
Usually we just banter over spelling and hyphens and so forth. But here at Macmillan I’m involved with linking any related British and American words new to the second editions of the online dictionary. Many of these new words haven’t yet made it across the Atlantic, thus being exclusive to one setting or another of the online dictionary, and some of these, I think, are worth the other side’s hearing. They tell us a lot about the respective countries they originate from, and often words that the dictionary would designate as ‘slang’ or ‘informal’ have some form of wit behind them.
And whose corpus of new words and slang is better? Are the British the keepers of the grand old language or should they concede ownership to the Americans? British is braw, but American is bitching. Let battle commence!
UK: argy-bargy (noun): noisy arguments
US: ass backwards (adverb): in an extremely confusing way, especially in a way completely opposite to the correct way, e.g. “Look, you put this together ass backwards.”
US: backgrounder (noun): an informal meeting in which a government official gives reporters extra information about a political situation
UK: barney (noun): a loud argument
US: bedroom community (noun): a place from where many people travel to a town to work
US: big tent (noun): a group or political party that includes people who have a wide range of beliefs or opinions and come from many different backgrounds
UK: blether (verb): to talk continuously about things that are not important
US: bitching (adjective): excellent
US: bodacious (adjective): excellent or impressive
UK: bodge (verb): to do something badly, especially to make or repair something badly because you do not have enough time or the right materials to do it properly
UK: bog standard (adjective): ordinary and not special in any way
UK: braw (adjective): very good, pleasant or attractive
US: bull session (noun): a long friendly discussion, especially among a group of men
UK: chancer (noun): someone who is always willing to take a risk in order to get an advantage, even if it means doing something that other people do not approve of
UK: chatterati (noun): educated middle-class people who like to express their opinions
UK: clanger (noun): an embarrassing mistake, especially while you are talking
UK: cobblers (noun): something that you think is silly or not true
US: coffee klatch (noun): a social occasion where people have conversations about unimportant things
UK: codswallop (noun): something that is silly or not true
Well, today I’ve only got through A-C. But some conclusions can already be drawn. The British are disapproving, wary bodgers and chancers, fearful of embarrassment and loud arguments. The Americans are a friendly, leisurely, enthusiastic, inclusive bunch, sometimes prone to confusion, ruled by devious politicians. Admittedly, this selection may have been warped by my preconceptions of the two countries …
One other thing to note is that American slang is far more likely to be subsequently adopted by the British than the other way around, due to cultural imports, in terms of technology, news and television programmes, and the fact that it’s always been harder to crack America.

Just an observation from an American: people often rearrange “ass backwards” to say “bass ackwards.”
I think it’s only partially due to a halfhearted attempt to avoid swearing, but more along the lines of expressing the screwed-upness of the situation.
Another note from an American, this time one living in Germany.
I thoroughly enjoyed this list of terms, many of them new to me, some long-known (e.g. bedroom community) or completely logical (e.g. backgrounder) to me.
The term “bodge” (UK) reminds me very much, in sound and in meaning, of “botch” — is there really a difference, or is this just a form of the old word “botch”?
And is “braw” related at all to “brawny”? A brawny fellow, depending on the circumstances, can be “very good, pleasant or attractive” 🙂 !
ass backwards is surely the american version of head over heels which can also be expressed arse over tit which means exactly the same thing.
Perhaps it would be interesting to see how and where these expresions arose and see if the army and navies of the relevent countries imported the phrase or if they are independent.
Isn’t “relevent” spelled “relevant?”
It is indeed: relevant.
In fact “braw” isn’t British but Scots (the dialect of lowland Scotland, whose most famous exponent is Robert Burns): see e.g. http://www.scots-online.org
It features in the semi-joking phrase “It’s a braw bricht moonlicht nicht the nicht”.
No connection with “brawny”, Rebecca: it’s a variant of “brave” in its original meaning of good or fine (as in a “brave new world”).
The UK equivalent of ass backwards is arse about face (could be regional).
UK for ‘bedroom community’ = ‘dormitory town’.
UK for ‘big tent’ = ‘broad church’.
I’d have said that in BrE “botch” means “to perform an action or task wrongly”, as opposed to “bodge” being something like “do a bad or incomplete, but not necessarily entirely ineffective, task”.