1. to remain cool; to not become angry; to be patient; used to tell someone to calm down or be more patient

1. The referee saw the two players shouting at each other and told them to keep their shirts on.

2. Keep your shirt on! Your car isn't even scratched!

3. Wait a minute! Keep your shirt on!

4. Keep your pants on! I’ll be with you in a minute.

5. "Aren't you ready yet?" "Keep your shirt on! I'll be ready in a minute."

6. Jane: Bob, we are just dying for some refreshments. Bob: Keep your pants on.