be on best behaviour



be on your best behaviour

  (British & Australian) also be on your best behavior (American & Australian)
to behave very well, usually because you are in an important or formal situation Now children, I want you all to be on your best behaviour when grandma arrives.
See also: behaviour, on

Common Names:

NameGenderPronouncedUsage
LiseLEE-se (Swedish, Norwegian, Danish), LEES (English), LEEZ (English)French, Swedish, Norwegian, Danish, English
Meiriona-Welsh
Rositsa-Bulgarian
NoËLleno-EL (French)French, Dutch
PercivalPUR-si-vəl (English)Arthurian Romance, English
Justynayuws-TI-nahPolish