- not of a formal, official, or stiffly conventional nature
- appropriate to everyday life or use
- denoting or characterized by idiom, vocabulary, etc, appropriate to everyday conversational language rather than to formal written language
- denoting a second-person pronoun in some languages used when the addressee is regarded as a friend or social inferior
WordReference Random House Learner's Dictionary of American English © 2026
in•for•mal /ɪnˈfɔrməl/USA pronunciation
adj.
WordReference Random House Unabridged Dictionary of American English © 2026- without formality;
casual:an informal visit. - not according to the official manner:informal proceedings.
- Linguisticssuitable to or characteristic of casual speech or writing:an informal use of a word.
- See colloquial.
in•for•mal
(in fôr′məl),USA pronunciation adj.
in•for′mal•ly, adv.
- without formality or ceremony;
casual:an informal visit. - not according to the prescribed, official, or customary way or manner;
irregular;
unofficial:informal proceedings. - Informal Terms, Linguisticssuitable to or characteristic of casual and familiar, but educated, speech or writing.
- Grammarcharacterizing the second singular pronominal or verbal form, or its use, in certain languages:the informaltu in French.
- in-3 + formal1 1595–1605
- 1. natural, easy. 2. unconventional. 3. See colloquial.
- 2. conventional.
Collins Concise English Dictionary © HarperCollins Publishers::
informal /ɪnˈfɔːməl/ adj
'informal' also found in these entries (note: many are not synonyms or translations):
a
- about
- agin
- and
- appro
- Auntie
- Aussie
- baccy
- bark
- beanbag
- Bear
- Beeb
- bellyache
- bellybutton
- binder
- Birmingham
- black box
- bloke
- blower
- blubber
- blue
- bluebottle
- bob
- body
- bone
- borstal
- box
- bring-and-buy sale
- briny
- Britain
- brolly
- Brummagem
- BSE
- bubbly
- buddy
- buy
- bye-byes
- call in
- cans
- candid
- candid camera
- casual
- cat cracker
- causerie
- ceilidh
- chair
- character
- chat
- chatty
- check