mad dog, n. — Green’s Dictionary of Slang

mad dog n.

[the effects]

1. in context of drink or drugs.

(a) strong ale.

1587

W. Harrison Description of England 150: There is such headie ale [...] commonlie called huffe-cappe, the mad dog, father-whoresome, angels food, dragons milke, go-by-the-wall, stride-wide, and lift-leg.

(b) (US, also MD) cheap wine, esp. the brand Mogen David 20/20.

1973		Cincinnati Enquirer (OH) Mag. 14 Oct. 44/2: Mad-Dog — M.D. Double 20 wine.
1986		L. Heinemann Paco’s Story (1987) 205: Well able to remember the medicinal smell of that cheap booze — ‘Mad Dog 20/20’, Unc called it.
1992		R.C. Cruz Straight Outta Compton 19: He was clutching a bottle of Mad Dog and taking swigs like it was nothing.
1996		P. Beatty White Boy Shuffle 98: Joe offered me a sip of pink swill from a pint of Mad Dog 20/20.
1996		Eble Sl. and Sociability 37: In a reverse process, an established acronym or letter name can be expanded. [...] MD (from Mogen David 20/20) becomes Mad Dog.
2004		C. Wine What you Make It 380: Arnetta you got the Thunderbird, I got the Night Train and Melanie you got the Mad Dog. Ugh! It was nasty ass shit but we kept drinking.
2009		T. Black Gutted 126: Some young heller with a bottle of Mad Dog in him.
2011		H. Marlin Best of Harry Marlin I 652: Never pay over three dollars a bottle for wine, or buy a brand name that mentions thunder, mad dog, night, train, or whistle.
2012		M. McBride Frank Sinatra in a Blender [ebook] I grabbed a container of vodka [...] and a bottle of Mad Dog 20/20.
2020		G. Armstrong Young Team 16: A bottle ae [...] MD 20/20 tae keep is mad-wae-it.

2001

ONDCP Street Terms 14: Mad dog — PCP.

2. (Aus.) an unsettled debt that the debtor refuses to pay, esp. at a public house.

1885		Bulletin (Sydney) 28 Feb. 12/1: Oh, Bayards! quitting this fair shore, / The grocer man will rave no more, / And, in the dreary eve, make scenes / About ‘those pig’s feet and sardines.’ / Outside a pub., as on you jog, / You need not fear the grim ‘mad dog’ / That yells, ‘I know your dirty tricks – / You keep away for three-and-six.’.
1900–10		Stephens & O’Brien Materials for a Dict. of Aus. Sl. [unpub. ms.] 42: MAD DOG: Aust. an account which the debtor will not pay, mostly used in reference to public houses.
1941		Baker Popular Dict. Aus. Sl.

3. in context of instability [SE mad dog; note mad dog v.].

(a) (US) a violent thug.

1980		E. Folb Runnin’ Down Some Lines 119: There is the outright [...] mad dog who actively seeks out situations in which to confront or assault others.
2012		T. Robinson ‘Roses at His Feet’ in Dirty Words [ebook] He wasn’t no mad dog. He had rules.

(b) (US black) a rebel, a non-conformist, one who refuses to accept their role in society.

1994

C. Major Juba to Jive.

1997		E. Little Another Day in Paradise 82: Ty gives Mel a stone mad dog. [Ibid.] 109: He pauses [...] pinning me hard. Got a good psychotic mad dog.
1998		Austin American-Statesman (TX) 14 Oct. 9/4: Texas Prison Gangs Slang [...] Mad dog: Hard stare.