Meaning of INFORMAL in English

INFORMAL

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.

Concise Oxford English dictionary.      Краткий оксфордский словарь английского языка.