p's and q's

plural noun

ˌpēz-ᵊn-ˈkyüz 

1

: something (such as one's manners) that one should be mindful of

… better watch his p's and q's when I get a six-gun of my own.

—Jean Stafford

2

: best behavior

… being on her p's and q's for two solid days was too much …

—Guy McCrone

Word History

Etymology

from the phrase mind one's p's and q's, alluding to the difficulty a child learning to write has in distinguishing between p and q

First Known Use

1779, in the meaning defined at sense 1

Kids Definition

p's and q's

noun

ˌpēz-ᵊn-ˈkyüz 

: something (as manners) that one should be careful about

always minded my p's and q's around my aunts and uncles