informal

not formal; "conservative people unaccustomed to informal dress"; "an informal free-and-easy manner"; "an informal gathering of friends"

not officially recognized or controlled; "an informal agreement"; "a loose organization of the local farmers"

used of spoken and written language

having or fostering a warm or friendly and informal atmosphere; "had a cozy chat"; "a relaxed informal manner"; "an intimate cocktail lounge"; "the small room was cozy and intimate"