Green’s Dictionary of Slang

1. (also finisher of the law) the hangman.

1696		Motteux (trans.) Gargantua and Pantagruel (1927) II Bk V 493: They will take pains to dance at a rope’s end, providently to save charges, to the no small disappointment of the finisher of the law.
1734		Grub St Journal 2 May 1/1: I imagine [...] that in point of order [...] the finisher of the law ought to draw up the conclusion [OED].
1833		Fraser’s Mag. VIII. 30: Thistlewood was suspended by the finisher of the law .
1846		Bell’s Life in Sydney 7 Nov. 3/2: J. Richards, whose countenance closely resembled that of our finisher of the law, Mister Green, was charged by the constable.
1869		Sportsman (London) 14 Aug. 4/1: Notes on News [...] He knew he was going to be strangled by the finisher of the law in a few seconds.
1885		Bulletin (Sydney) 22 Aug. 6/3: A born humourist was [...] lost to the world when Mr. Thomas Galvin, the genial, light-hearted ‘finisher’ of the noted Kilmainham (Dublin) Gaol, went under, full of years, ‘rheumatiz,’ and honours.

2. something that lit. or fig. puts an end to, discomfits or ‘does for’ someone; in boxing, a knockout blow.

1728		J. Dalton Narrative of Street-Robberies 28: He [...] delighted to see the Whores now and then put to their Shifts, that they might learn to live, when the Finisher of the Law had topp’d all their Cullies.
1820		Carlisle Patriot 9 Dec. 2: Don’t give a chance away, a finisher is only wanting.
1827		Sporting Mag. XX. 60: He gave him...four or five such finishers, as [etc.].
1834		Ely’s Hawk & Buzzard (NY) Sept. 6 n.p.: Sam [...] downed him. That was the finisher.
1843		‘Madison Tensas’ Louisiana ‘Swamp Doctor’ (1850) 174: That war my wust enemy, waitin’ for me to giv him a finisher, an’ I cuddent git at him.
1845		Bell’s Life in Sydney 27 Dec. 2/5: He very unfeelingly cut her short, by adding as an adjunct to her other qualifications that ‘she kept a brothel‘—this was a finisher and Jane was bound over.
1855		(con. 1831) Fights for the Championship 120: Byrne got away from a left-handed finisher.
1895		Reynolds’s Newspaper (London) 23 June 2/5: ‘He gave you a slash that would have killed a buffalo! S’pose you know it’s a finisher?’.
1906		Marvel 16 June 590: That’d be the finisher!
1911		E. Dyson ‘The Fickle Dolly Hopgood’ in Benno and Some of the Push 64: Never do nothin’ else, but jab ’em with a straight left ez they come in, savin’ me right fer a finisher.
1938		H.M. Anderson Strip Tease 41: The ‘crazy’ woman who came in to pick lemons off the wall put the finisher on him . When she emerged from the wings [...] he emitted an involuntary prize fighter’s ‘Ugh!’.
1940		T. Thursday ‘There’s Hicks In All Trades’ in All Sports Feb. 🌐 Next, the uppercut, [...] a counterpunch, and the one most used to score a finisher with.
1947		B. Schulberg Harder They Fall (1971) 45: The crash put the finisher on Danny’s chips.
1956		‘Ed Lacy’ Men from the Boys (1967) 124: Ya know I can do things that will make ya talk, beg for the finisher!

3. one who is capable of delivering a knock-out blow.

1828

‘A Flat Enlightened’ Life in the West II 89: Paddy had much the advantage of weight, and altogether had the appearance of a ‘finisher’ .

4. something that settles a dispute.

1836		T. Hook Gilbert Gurney 247: This was a finisher.
1949		Western Times 14 Apr. 4/5: ‘I suppose the Rissians [sic] thought that would put the finisher to it, and us would have to [...] shab off’.