informal /in-förˈməl/

1. Not of a formal or conventional nature
2. Characterized by lack of ceremony or formality
3. Relaxed, friendly, unceremonious
4. (esp of clothes) appropriate to everyday or casual use
5. (of speech or writing) having vocabulary, idiom, etc characteristic of conversational speech
6. (of a vote) invalid (Aust and NZ)

informalˈity noun

• spleens
• spleenstone
• spleenstones
• spleenwort
• spleenworts
• spleeny
• splenative
• splendent
• splendid
• splendide mendax
• splendider
• splendidest
• splendidious
• splendidly
• splendidness
• splendidnesses
• splendidous
• splendiferous
• splendor
• splendorous
• splendors
• splendour
• splendours
• splendrous
• splenectomies