Have the British corrupted any Americanisms in recent times?

Does the mangling of a common language go both ways?

They gave us chips and we made them fries. Their dustmen became garbage collectors. Biscuits became cookies.

Does it ever work the other way around, where an American word is turned into something different across the pond?

Maybe with automobiles? (trucks --> lorries? hoods to bonnets?)

We invented the yellow traffic light, and they made it amber.

Well, there is this current thread on Mohawk to Mohican.

Hamburgers are sometimes called beefburgers in Britain. (Only logical!)

Also, not quite the same thing, but related, many British people believe (wrongly) that the American term for a car’s bumper is “fender”. (Actually it is “bumper” on both sides of the Atlantic, and the American “fender” refers to a part of the car that has no name in British ENglish.)

Hmm? A fender is a “wing” in Britishese.

The term “ground beef” in the U.S. is changed to “minced beef” in the UK.

Maybe I’m misunderstanding the OP. The examples you’re citing aren’t things that were “corrupted” from British English, but things that were invented or came into common use after the two dialects had parted ways and each came up with separate terms for.

In the UK. Barbecue is grilling over an open flame

How about the British verb “to hoover”, as in to use a vacuum cleaner to clean a carpet/rug/floor? It’s obviously derived from the name of the American manufacturer of vacuum cleaners.

Yep - my wife and I ‘hoover’ with a ‘Vax’.

Most of the above are from GB to USA. We need a word that originates in the USA and got mangled on its way across the Atlantic. Movie (from moving image) to Cinema might be one.

Offhand I can’t think of any others, while there are dozens of USA to GB imports.

Elevators. American Elisha Otis invented what he called the “safety elevator” and founded the United Elevator Company, later the Otis Elevator Company. In Britain the Otis safety elevator is called a lift.

In America a fanny pack is a purse worn with a belt above the butt. In the UK, a fanny pack is a tampon. Pretty uncomfortable if you get that just slightly wrong.

The British apparently misuse the term ‘rain check’ (or cheque as they spell it) as a synonym for refund.

As originated in baseball, it’s a voucher issued to ticket holders for a rained-out game, allowing them to attend on a makeup date. You don’t get your money back. More broadly, it’s a slip given out by a store when they run out of stock that allows you to buy something later at the sale price.

They never quite got this distinction over there. Then again, you have to be careful about throwing around the word “misuse”. A good resource is the blog Separated By a Common Language, which delves into usage differences between US and UK English, without getting all tut-tutty about it.

No one in the UK would actually call a tampon a ‘fanny pack’ except as a joke. ‘Fanny’ is a euphemism for female genitalia, which makes the connection. In any case it would have more in common with an old fashioned sanitary towel.

I am not sure which way that difference went. Sweet Fanny Adams was a common euphemism when I was a lad. Fanny was a common enough name too and a contraction of Francis. How it became associated with a lady’s anatomy I can’t seem to discover.

No it isn’t. The “fanny” difference is that in US English it’s all about the arse, whereas in the UK it’s the front bottom, the lady-garden, the mimsy, the muff, the “insert euphemism”.

I don’t know how that’s relevant as the use of ‘minced’ pre-dates the US

Nope, whoever told you that is telling porkies, we don’t use “rain check” that way. In the UK the figurative sense of “rain check” for re-scheduling appointments/invitations to an unspecified date is used. If you used it in any other sense in the UK you’d get blank looks. Tbh I never realized that “check” in this phrase was used in the sense of “cheque”, I always assumed it was meant “stop”.

In many parts of the UK you’d not get any understanding at all of the term rain check. Perhaps something saved away as a reserve, who knows what else

Not only does “cinema” does not derive from “movie”, but it is also just as good a word in American English as it is in British. “Cinema” comes from the French, who were the first people to invent a commercially viable system for photographing and projecting moving pictures.

In both American and British English, “cinema” is the posh word for the thing. “Movies” is a vernacular, somewhat slangy term. The British equivalent (although many British people these days might prefer to use “movies”) is “flicks”.

Never heard “Rain Check” used in any other way than the intended and while I have never heard it stated explicitely it has always been clear by context that it means the postponement of an event.

Most Americanisms are reasonably self explanatory if unusual due to lack of familiarity but “Rocker Panels”* is one that caused me some confusion as it is not a term used here while a rocker box is the valve cover.

In any event I now have an American daughter in law to translate for me when the need arises.
*Sills.