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)

• you're welcome
• your humble servant
• your ladyship
• yourn
• Your Reverence
• yours
• yourself
• yourselves
• yours faithfully
• yours sincerely
• yours to command
• yours truly
• yourt
• yourts
• you scratch my back and I'll scratch yours
• youse
• youth
• youth club
• youth clubs
• youth court
• youth courts
• youth credit
• youth credits
• youth custodies
• youth custody