When the BBC did a piece a couple of years on British people’s most annoying Americanisms, “expiration date” instead of “expiry date” made the top 50. As Lynne Murphy observed, those people didn’t really have much cause for their annoyance, but the Google Ngram chart below indeed shows “expiration date” as preferred in the U.S. However, the two versions have been pretty close in Britain for the last fifty years.
Now, what of American “expiry date”? The graph shows it to be on the rise, and the ever-sharp-eyed Nancy Friedman reports a growing number of sightings, notably at the clothing and furnishings chain Anthropologie. I went to the company’s website and went far enough in the process of buying a $500 rug to come upon this:
At that point, I x-ed out of that tab as quick as I could and hightailed it out of there.
notoneoffbritishisms.com 
Or, as we say in Britain, “Best before date.”
Who we?
“Best before” refers to comestible products that might, just, if we’re lucky, poison a person ten or so years after the date referenced.
“Expiry” means the conclusion of a document’s or a proposal’s validity. My driving licence and e-Bay sales offers do not say “best before” which, to my mind, is – at best – baby-talk and – at worst – , weasel wordage,
Apologies for erratic punctuation at end of my latest pontification.
– Leroy Xavier XVII
A North Americanism which I reject on the grounds of illogicality is “entrée” for the main course of a meal. Long before I had ever travelled outside of N America or become used to eating in good restaurants this one irritated me. I’m Canadian; I speak French and studied the language in school so I knew, even as a child, that the word means “entry”. How can the main course be the entry?
The defintion of entrée as used in the culinary sense outside of N America is “a course which preceeds the main” and in some places, Australia, for example, it is normally used for a “starter” (N American, “appetizer”). In other words, it is the entry to the primary act of the meal, the main course. This makes sense but to call the main course the entrée fails the test of logic and clarity. It makes no sense.
I recently saw a US TV travel programme on Sydney in which the presenter pointed out that Australians “call the entrée the ‘main’ and call the appetizer the ‘entrée’.” Fair enough.
But what wasn’t fair, was downright unpleasant, was that she said it with a patronizing tone and smirk as if the poor, dumb Australians don’t know any better.
Sorry, Sunshine. They’re right and you’re wrong.
Wikipedia’s good on this – http://en.wikipedia.org/wiki/Entr%C3%A9e
Quite agree with you, Guy – the idea of the “entrée” being the exact opposite of what it says puzzled me too the first time I went to the States. Most of the language conventions covered on this site are debatable, but this, like the absurd US month-day-year date format, has no justification whatever.
Apart from anything else, I would have thought that Americans – famously contemptuous of French pretentiousness – would prefer to use the plain, straightforward English phrase “main course”.
On the actual topic of this thread, I can’t see a problem with either term – the British “expiry” is perhaps slightly preferable as being shorter than “expiration”, but otherwise, no big deal. My compatriot Matt W is muddying the water: “best before date” is not at all the same as “expiry date”, and anyway is being phased out in the UK in favour of “use by date”.
Next!
Use by and best before dates are different things. There are three different expiry dates used on food in the UK.
Use By: Perishable and may be dangerous after this date, found on things like milk. Means must not be eaten after this date.
Best Before: Goes stale or in some other way is not of the quality you might want, it won’t harm you but you might not want to eat it. Found on things like biscuits.
Sell by: Similar to best before but would be a little earlier. At that date would have too short a shelf life when the purchaser got home. Use pretty quickly if that date has been reached.
The only one that indicates a danger is use by the other two are informative about quality either for the consumer or the retailer.
I have been thinking about this ever since I read it a couple of weeks ago and I realised the word ‘expiration’ carries implications for me of breathing out. I looked it up and that is actually what it says – the word ‘expiration’ is a technical or medical term for breathing out. I must have come across it decades ago when I did my Biology O level. ‘Expiry’ is very much the UK usage. Obviously to ‘expire’ also means ‘to die’.
Your definition of expiration as breathing out is the SECONDARY definition, though.
Expiry sounds like something a child that can barely talk yet would say.