n. 25B6; noun that's enough of your cheek! : IMPUDENCE, impertinence, insolence, cheekiness, presumption, effrontery, gall, pertness, impoliteness, disrespect, bad manners, overfamiliarity, cockiness; answering back, talking back; informal brass (neck), lip, mouth, chutzpah; Brit. informal sauce, backchat; N. Amer. informal sass, sassiness, nerviness, back talk; archaic assumption.
25B6; verb they were cheeking the dinner lady : ANSWER BACK, talk back, be cheeky, be impertinent; Brit. informal backchat; N. Amer. informal sass, be sassy.