Green’s Dictionary of Slang

(US) drunk.

1737		B. Franklin ‘Drinkers Dict.’ in Pennsylvania Gazette 6 Jan. in AS XII:2 90: They come to be well understood to signify plainly that A MAN IS DRUNK. [...] Cock’d.
1821		N.-Y. American 21 Nov. 2/6: They had seen him ‘merry,’ ‘well to live,’ ‘pretty well cock’d,’ &c but they had not seen him so drunk that he could not stand up.
1834		Ely’s Hawk & Buzzard (NY) Mar. 22 2/3: If he does get cocked, it is nobody’s business.
1844		Stirling Obs. 19 Sept. 3/3: [from US press] Drunkeness Defined — [...] high-corned, cocked, shaved, disguised, jammed, [...] smashed, [...] snubbed, [...] battered [...] soaked, [...] bruised.
a.1856		Burlington Sentinel in Hall (1856) 461: We give a list of a few of the various words and phrases which have been in use, at one time or another, to signify some stage of inebriation: [...] cocked.
1881		Trumble Sl. Dict. (1890).
1928		R. Carr Rampant Age 12: Fellows who smoked and had hot dates and even got cocked on corn licker! [Ibid.] 26: We could all get cockeder’n hell.
1932		J. O’Hara ‘I Never Seen Anything Like It’ in New Yorker 3 Sept. 35/1: One of them goes over and shakes Paddy but they coulda been an oithquake and Paddy wouldn’ta moved. Not Paddy when he’s cocked.
1967–8		Baker et al. CUSS.
1977		Fidrych & Clark No Big Deal 80: Bob would say to me, How can you drink a six-pack every night? [. . . .] And I’d say, Bob, I’m just bored, y’know? I’m bored, man. If I had a chick I wouldn’t be—y’know, getting half as cocked as I am.