1. Not formal
   "conservative people unaccustomed to informal dress"; "an informal free-and-easy manner"; "an informal gathering of friends" 
2. Not officially recognized or controlled
   "an informal agreement"
   - loose 
3. Used of spoken and written language 
4. Having or fostering a warm or friendly and informal atmosphere
   "a relaxed informal manner"
   - cozy [N. Amer], intimate, cosy [Brit, Cdn]

See also: casual, colloquial, common, conversational, daily, epistolary, epistolatory, everyday, folksy, formality, formalness, free-and-easy, friendly, informality, informally, nonliterary, slangy, subliterary, unceremonial, unceremonious, unliterary, unofficial, unrhetorical, vernacular, vulgar

Antonym: formal

Encyclopedia: Informal

• prestidigitator
• prestige
• correlational
• correlational analysis
• correlational statistics
• correlative
• correlatively
• correlativity
• correspond
• correspondence
• correspondence course
• correspondence school
• correspondent
• corresponding
• correspondingly
• corrida
• corridor
• corrie
• corrigenda
• corrigendum
• corrigible
• corrival
• corroborant
• corroborate
• corroborating evidence