Informal definition
An informal gathering of friends; a relaxed, informal manner.
Informal discourse.
An informal agreement.
- Not according to prescribed or fixed customs, rules, ceremonies, etc.
- Casual, easy, unceremonious, or relaxed.
- Designed for use or wear on everyday occasions.
- Not requiring formal dress.
- Designating or of the words, phrases, and idioms characteristic of speech or writing that is casual, ordinary, unceremonious, etc.; colloquial.
An example of informal used as an adjective is informal clothing, such as comfy casual jeans and a sweatshirt.
Informal clothes.