- Not formal or ceremonious.
- an informal get-together
- Not in accord with the usual regulations.
- an informal agreement
- Suited for everyday use.
- informal clothes
- (of language) Reflecting everyday, non-ceremonious usage.
- (gardening) Not organized; not structured or planned.
- (not formal or ceremonious) casual
- (not in accord with the usual regulations) unofficial
- (suited for everyday use) casual
- (language: reflecting everyday, non-ceremonious usage) colloquial
- French: informel
- German: informell, unförmlich, zwanglos
- Italian: informale
- Portuguese: informal
- Russian: неформа́льный
- Spanish: informal
- French: informel, familier
- Italian: informale, colloquiale, familiare
- Russian: разгово́рный
- Spanish: familiar