Being exceptionally keen Anglophiles and fond followers of every linguistic tic and nuance that comes from the British Isles, you won’t need to read this. But that does not mean it can be left unsaid.
For reasons I am not entirely clear about, there seems to be a relatively common misunderstanding around the word cheerio and when it should be used. It might have something to do with the breakfast cereal, or because it’s a nice friendly sort of a word that you can practice that ‘British’ accent with, but I’ve seen a few instances of people attempting to use it to say hello—most commonly in their impression of a stiff-upper-lipped English gent— and that’s just plan wrong.
Cheerio never, ever means hello. Quite the opposite, in fact. If you doff an imaginary bowler hat and offer a friendly “cheerio!” at a first meeting, you’re saying goodbye. The breakfast cereal is an entire bowl of goodbyes. Tasty goodbyes. Friendly goodbyes. The kind of breezy goodbye you would say to a loved one if you wanted to minimize any anguish they may feel until next you meet. The kind of goodbye that would be applicable if you were leaving to go to war and your entire family had turned out to sobbingly wave you off, unsure if they would ever see you again, and you had to try and keep things light and airy, or you’d never leave.
(You can hear it just after “bonsoir old thing” and before “chin-chin”)
It is not the cold goodbye of a wife leaving her cheating husband for the final time. It is not the angry goodbye of a father cutting his daughter from his will. It is not the sobbing goodbye of a child being left at nursery for the first time (although it may come their way from the parents).
No, cheerio is the jaunty adieu one might adopt either because you are Bertie Wooster and everything is genuinely tickety-boo, or if the world is about to collapse and a brave face is required. A fare-thee-well for deliberately chipper people.
But never, ever a fond hello. That’s the sort of thing nations fall out over.