Other forms: cheerios
Cheerio is a cheerful goodbye, in British use. Cheerio then, say cheerio, cheerio for now.
It is dated and warm, and it belongs to older speakers and to the telephone. It is a goodbye and not a toast; that is cheers, which does both jobs. In America the word is a breakfast cereal and nothing else.
1nouncheerioA cheerful goodbye, in British use.
“"Cheerio, then, see you next week!" she called as she left the shop.”
cheerio is a farewell.
From cheer or cheery plus the -o ending, British, from the early twentieth century.
From cheer and/or cheery o.
Etymology from Wiktionary, CC BY-SA