on their best behavior

idiom

Definition of on their best behavior

: exhibiting proper behavior The children were all on their best behavior at the museum.

Comments on on their best behavior

What made you want to look up on their best behavior? Please tell us where you read or heard it (including the quote, if possible).

WORD OF THE DAY

tired or exhausted

Get Word of the Day daily email!

Test Your Vocabulary

Where in the World? A Quiz

  • peter bruegel tower of babel painting
  • What language does pajama come from?
Spell It

Can you spell these 10 commonly misspelled words?

TAKE THE QUIZ
Bee Cubed

Test Your Knowledge - and learn some interesting things along the way.

TAKE THE QUIZ
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!