Cheerio is a British colloquialism formed from cheer + the interjectional ending -o (early 20th century), used as a friendly farewell. Cheer is ultimately from Old French chiere ('face, mood'). The historical trail runs through chiere in Old French and cara in Latin. Morphologically, cheerio is transparent: a British colloquialism formed from cheer + the interjectional ending -o (early 20th century), used as a friendly farewell. Used as an intj and noun, cheerio now means "a chiefly British expression used as a farewell", so the present definition can be read against the older forms and meanings. The same lexical family is also visible in related forms such as cheer and cheery. The result is a borrowed or transmitted form whose modern spelling carries a compact record of its route into English.