informal (
http://definr.com/informal)
adj 1: not formal; "conservative people unaccustomed to informal
dress"; "an informal free-and-easy manner"; "an
informal gathering of friends" [ant:
formal]
2: not officially recognized or controlled; "an informal
agreement"; "a loose organization of the local farmers"
[syn:
loose]
3: used of spoken and written language [ant:
formal]
4: having or fostering a warm or friendly atmosphere;
especially through smallness and informality; "had a cozy
chat"; "a relaxed informal manner"; "an intimate cocktail
lounge"; "the small room was cozy and intimate" [syn:
cozy,
intimate]