Green’s Dictionary of Slang

1. (orig. US, also knocking-off time, knock-off time) time to leave or take a break in work, the end of the day; the act of ceasing work; also attrib.

1821–6		‘Bill Truck’ Man o’ War’s Man (1843) 165: Knock-off is it, at last? [...] and it’s no more than time.
1876		Sheffield Indep. 23 Dec. 15/1: After ‘knock off’ time, Mrs Mahoney’s was crowded with a mob of customers.
1892		J.R. Couper Mixed Humanity 49: At ‘knock-off time’ Senior and his gang of Kaffirs went to receive their week’s wages.
1892		Launceston Examiner (Tas.) 26 Mar. 2/5: When knocking off time came the contract [...] was, of course, still incomplete.
1906		E. Dyson Fact’ry ’Ands 130: Sis Twentyman was the first in the dressing-room at knock-off time.
1910		Bulletin (Sydney) 18 Aug. 10/1: ‘Knock-off time!’ at last I mumble. ‘Why, oh why must people eat?’ / Then methodically hurry homeward on reluctant feet.
1925		Z.N. Hurston Spunk (1995) 953: Ah wuz glad when knockin’ off time come.
1937		J. Curtis You’re in the Racket, Too 21: It was as good a way as any of filling in the few moments before knocking-off time.
1957		‘Nino Culotta’ They’re a Weird Mob (1958) 41: Knock off time matey.
1961		R.S. Close With Hooves of Brass 137: ‘I’ll give a whistle when it’s knock-off for lunch’.
1976		D. Ireland Glass Canoe (1982) 74: He [...] worked at the bar — drinking middies — till four, which was knock-off time.
1983		A. Cannon Bullocks, Bullockies and Other Blokes 7: But the bullocks knew it was knock-off time.
1990		A.C. Houlsby Construction and Design of Cement Grouting 163: The approach of knock-off time is a factor to keep in mind (the crews certainly do!).
2005		J. Endersby Monsters In The Dark: A True Story 54: So it ‘was knock off time for the day staff before the alarm’ was raised.
2007		L. Redhead Cherry Pie [ebook] Everyone but the dishpigs repaired to the bar for knock off bevvies.
2020		G. Disher Consolation 25: ‘I’ll ask the boys at knock-off’.

2. attrib. use of sense 1.

1914		Sport (Adelaide) 11 Sept. 4/3: You showed your hand too plainly [...] after knock off time.
1917		Rising Sun 8 Feb. 4/2: I heard all the factory whistles [...] blowing their ‘knock-off’ call.
1919		C.J. Dennis ‘The Vision’ in Chisholm (1951) 116: An’ when the knock-off whistle blew, Ben Murray he came by.
1926		K.S. Prichard Working Bullocks 218: Their dinner had to be ready when the knock-off whistle blew.
1941		K. Tennant Battlers 285: The wind, that raged so industriously by day, always downed at sunset, as abruptly as if it had heard a knock-off whistle blow.
2020		D. Whish-Wilson Shore Leave 28: [W]orkers from [...] the nearby docks flooded in around knock-off time.

3. (orig. US) a period away from work; a holiday.

1899–1900

C.L. Cullen Tales of the Ex-Tanks 178: Ten days, which was to be the period of his knock-off after nine solid months on the range.

4. in Und. uses.

5. an act of sexual intercourse.

1959

A. Zugsmith Beat Generation 37: Many women were as shocked by a day-time hosing as by the knock-off itself.

6. a fake, a copy; used in the fashion trade to describe cheap copies of ‘designer’ garments, cheap reproductions of antiques etc.

1966		N.Y. Times 25 Jan. 44: Copying designs to sell for less has a name in the industry. It is called the ‘knockoff’.
1971		Time 25 Jan. 38: Private customers paid $700 for the original; buyers, intent on knockoffs, paid close to $1,500.
1990		R. Campbell Sweet La-La Land (1999) 8: Quickie knockoffs of The Omen and The Exorcist.
1997		Mad mag. Nov. 35: How do you think he felt seeing white people in Nike sneakers while he wore only knockoffs from Payless?
2001		J. Stahl Plainclothes Naked (2002) 159: Florence pranced in, wrapped in an off-the-shoulder black Armani knockoff.
2008		G. Pelecanos Way Home (2009) 23: Frank Lloyd Wright knockoffs, many embassies.
2015		http://grey-magazine.com July 🌐 I’m approached by a girl dressed up as if for a date. She’s in her best Baby Phat knock-offs, trying so hard.
2015		G. Disher Heat [ebook] They’d turn up in their Armani knock-offs as if there were paparazzi waiting. Sad, silly, under-educated boys.
2017		L. McInerney Blood Miracles 6: The market offers so many MDMA knock-offs: PMA, NBOMe, MDE, alphabet broths of second-rate stimulants.
2020		C. Hiaasen Squeeze Me 29: Teabull had now replaced purloined valuables with cheap knockoffs.