adj. 1 without ceremony or formality (just an informal chat). 2 (of language, clothing, etc.) everyday; normal. informal vote NZ & Austral. an invalid vote or voting paper. informality n. (pl. -ies). informally adv.
INFORMAL
Meaning of INFORMAL in English
Concise Oxford English dictionary. Краткий оксфордский словарь английского языка. 2012