on one's best behavior

Also, on one's good behavior. Very polite, as in Mother told the children to be on their best behavior during Grandma's visit, or The whole staff were on their good behavior while the client inspected the premises. [Late 1600s]

Common Names:

Name	Pronounced	Usage
Toshe	TO-she	Macedonian
Luisinho	-	Portuguese
Arnifrid	-	Ancient Germanic
Aleck	['ælik]
Medhat	-	Arabic
Sanaa (2)	-	Eastern African, Swahili