"impudence," 1835, back-formation from sassy. The verb is first recorded 1856, from the noun. Related: Sassed; sassing. Sass (n.) as a variant of sauce is attested from 1775.
The teacher punished the students who were sassing all morning
don't sass me!
don't give me any of your sass
sash
sashay
sashimi
Saskatchewan
sasquatch
sass
sassafras
Sassanid
Sassenach
sassy
SAT