throw off, v. — Green’s Dictionary of Slang

throw off v.

1. in forms of speech.

(a) (orig. UK Und., also throw off on) to deride, to ridicule, esp. under the guise of apparent pleasantry.

1796		T. Morton Way to Get Married in Inchbold (1808) XXV 10: Curse the quiz! I’ll throw off a little – Perhaps you’ve not been in town lately.
1812		Vaux Vocab. of the Flash Lang. in McLachlan (1964) 274: throw off: to talk in a sarcastical strain, so as to convey offensive allusions under the mask of pleasantry, or innocent freedom; but, perhaps, secretly venting that abuse which you would not dare to give in direct terms; this is called throwing off; a practice at which the flash ladies are very expert, when any little jealousies arise among them.
1823		‘Jon Bee’ Dict. of the Turf, the Ring, the Chase, etc. 173: Throwing-off — talk about any one in his presence, always adversely, and generally in the third person.
1851		Bell’s Life in Sydney 2 Aug. 3/2: She was throwin’ off in such a way as no human being could bear it. She actually spit upon the ground.
1865		Empire (Sydney) 5 Feb. 3/1: Recently bis money began to grow scarce and his charmers affection cooled proportionately, in other words she began to ‘throw off on him,’ as the slang phrase goes.
1900		Bulletin (Sydney) 24 Mar. 10/3: The big Australian dailies, which never lost an opportunity of ‘throwing off’ at the U.S. press during the Spankee war, now labor painfully in their attempts to imitate the despised ’Murkan papers.
1911		E.S. Sorenson ‘Shearer & Rouseabout’ Life in the Aus. Backblocks 247: Some hard case is bound to ‘throw-off’ at him at such times, and he sees apoplectic faces both sides of him [...] and the man-over-the-board remarks, ‘I’d leave him enough skin to start another coat with, Tom.’.
1915		M.O. Pollard ‘Terms From The Tennessee Mountains’ in DN IV:iii 243: throw off on, v. phr. To make fun of; also, to say uncomplimentary things about. ‘He threw off on me something awful when I wore them.’.
1920		Cairns Post (Qld) 4 Aug. 4/5: The official Labour press is actually ‘throwing off’ at [...] the new Governor of Queensland because he is a Jew!
1923		R. McAlmon Companion Volume 194: Me bored stiff [...] and you throwing off on me all the time because you’re so bored too.
1939		K. Tennant Foveaux 35: Always throwing off about my family, my wife is.
1951		Cusack & James Come in Spinner (1960) 23: No one would throw off at him going round with a girl twenty years younger.

(b) (UK Und.) to boast of one’s successful crimes.

1812		Vaux Vocab. of the Flash Lang. in McLachlan (1964) 274: To begin to talk flash, and speak freely of robberies past, or in contemplation, when in company with family people, is [...] termed throwing off; meaning to banish all reserve, none but friends being present; also, to sing when called on by the company present.
1823		Egan Grose’s Classical Dict. of the Vulgar Tongue [as cit. 1812].

2. (US, also throw off on) to abandon, to neglect; to cease from an action.

1859		Wkly Varieties (Boston, MA) 3 Sept. 8/2: A certain Mr B—r had better leave the negro wenches alone [...] or his girl will throw off on him.
1872		‘Mark Twain’ Innocents at Home 337: He never throwed off on his mother [...] he looked after her and took care of her all the time.
1876		(con. c.1840) ‘Mark Twain’ Tom Sawyer 193: I ain’t going to throw off on di’monds. Some of ’em’s worth twenty dollars apiece.
1895		Crowe Aus. Sl. Dict. 85: Throwing Off, betraying your partner in gambling.
1906		A. Adams ‘Drifting North’ Cattle Brands 🌐 This is no time to throw off, or refuse to be sociable.

3. (UK Und.) to (break) open.

1865

Leaves from Diary of Celebrated Burglar 99/1: When the coast was clear, Jack ‘nipped’ up to the door and ‘threw it off’ immediately.

4. (US) to lose a contest deliberately.

1965		H. Williamson Hustler 93: Now if a sucker was bettin’ a small portion of money on Jesse, I would let him win until this guy’s bet got larger. If I couldn’t beat Jesse out, he would throw off [f.n.] just enough to make the game look right, and let me win [f.n. Not play as hard].
2001		D. Jenkins Money-Whipped Steer-Job 167: They were throwing off, losing games to gimps, and they didn’t care because they were too rich.

5. (Aus. prison) to avoid an issue.

1990

Tupper & Wortley Aus. Prison Sl. Gloss. 🌐 Throw off. To avoid the issue. For example a prison officer would be accused of throwing off where he refused to make a decision about a request. Alternatively a prisoner may feign ignorance when confronted about an issue. Sometimes just throw.