Green’s Dictionary of Slang

(Irish/US) one who automatically takes an oppositional stance, usu. out of envy or spite.

1904		Eve. Star (DC) 12 Sept. 4/2: Some persons [...] appear to get their highest enjoyment out of dissatisfaction. There are persons who can not talk except in opposition. There are so many chronic ‘aginners’ .
1922		Lubbock Avalanche (TX) 10 Jan. 6/1: A lot of folks stayed at home who should have been intersted enough [...] to vote [...] and let a few of the ‘aginners’ defeat the proposition.
1927		Nation and Athenaeum 593/1: Mr. Cook is [...] an out and out ‘aginner.’ He is not merely agin the Government, but he is agin anything that does not involve what he calls ‘a complete change in the social structure’.
1935		Lit. Digest CXX 38/1: But as an ‘aginner’ he is a very good ‘aginner.’ And the thing he would be ‘agin’ next year would be the New Deal.
1948		Dr. H.M. Tietbout on A.A. Grapevine Inc. 🌐 When the alcoholic is sick he is an ‘aginner’ [...] The ‘aginner’ cannot enjoy life.
1975		Jrnl. Clinical Psychol. XXXI 516: The ‘aginner’ is rarely for something, but he is readily against the beliefs and actions of others.
1984		W.D. Barnard Dixiecrats and Democrats 20: Sparks was ‘a born aginner,’ Sherlock said, ‘a reactionary bourbon from Barbour’ who ‘fought every humanitarian program that Bibb Graves ever advanced’.
1992		W.F. Buckley In Search of Anti-Semitism 3: Mr. Sobran is the best ‘Aginner’ I have ever seen. Down my part of the country, an Aginner is a feller who is ‘against’ most everything in general.
2004		Dallas Arena 18 Dec. 🌐 We are not just aginners intending to stop this Park Cities coup d’état of our Dallas city government, we are supporters of the status quo.
2011		Jernigan & Rhodes Those Smoke-Filled Rooms 197: He was an ultraconservative banker and was what I call an ‘aginner’. He was ‘aginst’ any bill that called for the state to spend money.