1. Not in the regular, usual, or established form; not according to official, conventional, prescribed, or customary forms or rules; irregular; hence, without ceremony; as, an informal writing, proceeding, or visit.
2. Deranged in mind; out of one's senses. [Obs.]
These poor informal women. --Shak.
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"
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,