Green’s Dictionary of Slang

cheek.

1866		T. Winthrop Life in the Open Air 46: Personal ‘sassiness’ is a trait of which every Yankee is proud.
1880		Bismarck Trib. (ND) 9 July 2/2: De ole man called it to himself sassiness, an’ impudence.
1892		Life Mag. 20 310: Don’t get sassy, because sassiness don't go in this game.
1903		W.E.B. DuBois Negro Church 203: The youth is apt to mistake ‘sassiness’ for courage, mannishness for manliness, and false pride for self-respect.
1904		H.R. Martin Tillie 299: He stared at her for a moment — then answered with a mildness that amazed his wife even more than Tillie 's ‘sassiness’ had done.
1910		Godwin’s Wkly (Saly Lake City, UT) 19 Feb. 14/2: There is a good deal of fighting blood in both our families, dating back to the sassiness of ’76.
1947		K. Lumpkin Making of a Southerner 86: Could not men recount a hundred tales with slight variations of Negroes ‘becoming very insolent,’ of ‘uppityness,’ ‘sassiness’.
1978		Stage (London) 5 Oct. 21/4: Elvis Payne and Patrick Muray were full of vitality and [...] a knd of cockney sassiness.

1. (US) a cheeky child; a saucy young woman.

1857		J. Loud Orphan Boy 49: What do you stay here for, you young sass-box?
1871		E. Eggleston Hoosier School-Master (1892) 130: Yes, I war, too, you little sass-box!
1885		J.T. Trowbridge Farnell’s Folly 45: ‘What’s that, sass-box?’ His mother made a dash at him.
1894		Bill Nye Hist. U.S. 241: The old man, it seems, at first told the boy that he had better come down [...] but the young sass-box — apple-sass- box, I presume — told him to avaunt.
1904		Monroe City Democrat (MO) 26 May 2/2: ‘I’ll let ye know how ye call my gran’daughter “red head,” ye little sass-box!’ .
1907		J.W. Carr ‘Word-List from Hampstead, N.H.’ in DN III iii 198: sass-box, n. A saucy or pert woman or child.
1915		M.G. Hayden ‘Terms Of Disparagement’ in DN IV:iii 210: sass-box, impudent child. ‘The little sass-box told me to go to grass.’.
1933		Taunton Courier 26 Apr. 10/3: Sass-box — ‘Sarce box’ in Somerset — impudent fellow or girl.
1983		S. King Christine 503: She looked irritated for a moment, then smiled. ‘Ye’re a sassbox, Dennis Guilder,’ she said.

2. (US) the mouth.

1915

Washington Herald (DC) 28 Nov. 27/1: ‘Thar ’yer blarsted yankee! That’ll hold yer sass-box shut!’.

(US) a sarcastic and witty person.

2005		Urban Dict. 11 Aug. 🌐 sasshole a sassy person who gives a lot of sass .
2014		Eble UNC-CH Campus Sl. Spring 2014.

(US/W.I.) verbal aggression.

1983		T. White Catch a Fire 132: Dere would be some fockin’ donkey dung sass-mouth.
2004		P. Jones Color of Family 27: There was positively no cause for your sass-mouth, girl.

(US) talking in a cheeky manner.

2001		G. Pelecanos Right As Rain 124: Earl didn’t understand why Ray didn’t just backhand the girl when she got to sass-talking like she was prone to do.
2010		E. Silver Sins of the Heart n.p.: He wondered why she was all swagger and sass talking to him.