informal informal /ˌɪnˈfɔrməl/

adjective

1. () Not formal  ( informal )
   not formal
    Conservative people unaccustomed to informal dress
   conservative people unaccustomed to informal dress
    An informal free-and-easy manner
   an informal free-and-easy manner
    An informal gathering of friends
   an informal gathering of friends
   
2. () Not officially recognized or controlled  ( informal , loose )
   not officially recognized or controlled
    An informal agreement
   an informal agreement
    A loose organization of the local farmers
   a loose organization of the local farmers
   
3. Used of spoken and written language  ( informal )
   used of spoken and written language
   
4. Having or fostering a warm or friendly and informal atmosphere  ( cozy [ N. American] , informal , intimate )
   having or fostering a warm or friendly and informal atmosphere
    Had a cozy chat
   had a cozy chat
    A relaxed informal manner
   a relaxed informal manner
    An intimate cocktail lounge
   an intimate cocktail lounge
    The small room was cozy and intimate
   the small room was cozy and intimate