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]
Words nearby on one's best behavior
How to use on one's best behavior in a sentence
Added to drinking water at concentrations of around one part per million, fluoride ions stick to dental plaque.
In his view, a writer has only one duty: to be present in his books.
Yet this, in the end, is a book from which one emerges sad, gloomy, disenchanted, at least if we agree to take it seriously.
The best comparison here for an American audience is, well, Internet stuff.
Just the hard-on before you shoot unarmed members of the public.'Babylon' Review: The Dumb Lives of Trigger-Happy Cops|Melissa Leon|January 9, 2015|DAILY BEAST
Practise gliding in the form of inflection, or slide, from one extreme of pitch to another.Expressive Voice Culture|Jessie Eldridge Southwick
He alludes to it as one of their evil customs and used by them to produce insensibility.
There was a rumor that Alessandro and his father had both died; but no one knew anything certainly.Ramona|Helen Hunt Jackson
Truth is a torch, but one of enormous size; so that we slink past it in rather a blinking fashion for fear it should burn us.Pearls of Thought|Maturin M. Ballou
We resolved to do our best to merit the good opinion which we thus supposed them to entertain of us.