#54

cheer·i·o [cheer-ee-oh, cheer-ee-oh] Pronunciation Key - Show IPA Pronunciation interjection, noun, plural cheer·i·os. Chiefly British
–interjection
1.
good-bye; good-bye and good luck.
2.
(used as a toast to one's drinking companions.)
–noun
3.
a good-bye or farewell.
4.
a toast of “cheerio!”

[Origin: 1905–10; see cheero; source of -i- is unclear]