From Norman French, "face, merry faces, festivity"; from Late Latin, "head".
The sense of smiling, merry expression, good cheer, cheerful, is well attested in literature. "Cheers" is a versatile modern expression. I have heard it as "thanks", "drink well" (of course), and yes even "see you later".
this being my point. how do you know that what you were hearing wasn't someone saying thanks as they were leaving?
If someone said ‘cheers’ to me when parting, I’d interpret it the same way as if they’d said ‘thanks’ — which could be slightly strange, depending on the situation.
Maybe it is a conflation of cheers (smiles, thanks) and cheerio (old-fashioned familiar good-bye).
Possibly also because of the phonetic similarity with "ciao"?
https://en.wikipedia.org/wiki/Eggcorn
> An eggcorn is the alteration of a word or phrase through the mishearing or reinterpretation of one or more of its elements, creating a new phrase which is plausible when used in the same context. Thus, an eggcorn is an unexpectedly fitting or creative malapropism. Eggcorns often arise as people attempt to make sense of a stock phrase that uses a term unfamiliar to them, as for example replacing "Alzheimer's disease" with "old-timers' disease", or William Shakespeare's "to the manner born" with "to the manor born". The autological word "eggcorn" is itself an eggcorn, derived from acorn.
https://www.reddit.com/r/AskUK/comments/17tzcl5/comment/k915... says
> I certainly use it as a goodbye - typically after meeting someone in the street and stopping to chat, but also generally. Also as an informal signoff for email and saying goodbye over telephone.
>
> 64M British, brought up in London.
Now, I'm having second thoughts. Would I say it to a baker after buying a pastry? Yes. If I ran into a friend while out on a trip would I say it? No, I don't think so, but do I? Maybe as in "good seeing you"? How confusing.
Person seeing me walk out the door: "Cheers! See you tomorrow!".
you're suggesting a family member might say this as you were leaving?