Green’s Dictionary of Slang

1. a commission (on a financial or other transaction); thus as v., to work as a commission merchant.

1864		C.W. Wills Army Life of an Illinois Soldier (1996) 93: Told her we’d give her a commish as chief taster.
1870		W.W. Fowler Ten Years In Wall Street 81: ‘Seller three,’ rejoined O, ‘or regular?’ ‘Nothing up! and buyer three.’ ‘No commish,’ &c.
1887		Bulletin (Sydney) 22 Oct. 8/4: The cash was immediately drawn, the black mailer despoiled of his £10 commish, and now it’s very dangerous to ask this very highly respected citizen whether he can ‘put you on to making £40 for a slight consideration!’.
1895		Truth (Sydney) 5 May 4/8: I always bargain for my little 10 per cent ‘comish’ before I start.
1905		‘Hugh McHugh’ You Can Search Me 96: ‘You are a commission merchant in Springfield, Ohio?’ [...] ‘I’ma used to was,’ Skinski corrected. ‘There was a time when I commished for fair.’.
1913		J. London Valley of the Moon (1914) 455: From now on it’s horsebuyin’ on commish.
1925		E. Jervis 25 Years in Six Prisons 136: The ‘salaams’ had been getting lower and lower from the salesman at the thought of the rich ‘commish’.
1934		C. Stead Seven Poor Men of Sydney 88: I get a commish.
2013		Esquire 1 Sept. 🌐 He was on a sales call about to land a cushty deal and nail a wad of commish.

2. (US milit.) a commission in the forces.

1891

A.R. Calhoun Love, the Victor 223: ‘I got a commish to raise an independent rifle compiny, an’ kinder scout round’.

3. (also comish) a commissioner (usu. in police situations).

1895		Tammany Times 5 382: He caught onto the Bowery slang, and said: ‘Me fren’s, I’m wid yer. I, Rosey, de Perlice Commish an’ Commish Warin’ are wid yez’.
1911		D. Runyon ‘Blacklisted’ in Wash. Post 21 Mar. 8/3: Blacklisted? Sure! An’ the National Commish makes it foller wherever I hide.
1917		T.A. Dorgan in Zwilling TAD Lex. (1993) 28: (The ‘National Game’) {Picture of a woman wearing an apron marked:} National commish.
1930		E.A. Clancy ‘Flies on the Ceiling’ in Detective-Dragnet May 🌐 Any time Mrs. Million-bucks of Park Avenue loses her pet dog, she can get the commish on his private phone.
1946		W. Winchell On Broadway 28 June [synd. col.] When a columnist informed him the shot officer’s wife needed hospitalization [...] the commish went into action.
1952		W. Winchell On Broadway 6 Aug. [synd. col.] The Mayor’s choice to succeed Police Commish Monaghan [...] is Third Deputy Aaron Frank.
1991–96		The Commish [ABC-TV series].
2017		D. Winslow The Force [ebook] Hizzoner would fire the commish, except it would look like what it is.