Read the dictionary definition of informal. All definitions for this word.
1. not formal
1. conservative people unaccustomed to informal dress
2. an informal free-and-easy manner
3. an informal gathering of friends
2. used of spoken and written language
3. having or fostering a warm or friendly and informal atmosphere
1. had a cozy chat
2. a relaxed informal manner
3. an intimate cocktail lounge
4. the small room was cozy and intimate
4. not officially recognized or controlled
1. an informal agreement
2. a loose organization of the local farmers