Green’s Dictionary of Slang

the morning; the very early hours after midnight; also attrib.

1776		A.R. Robbins Journal (1850) 6: All our people at and near the landing ; exercised and walked around with the officers in A. M .
1889		Century Dict.
1907		B. Fisher A. Mutt in Blackbeard Compilation (1977) 18: It took a couple of jolts of lemon sour to round him this a.m.
1918		R. Lardner Treat ’Em Rough 51: I thought maybe they had missed the A.M. trains and would come later.
1922		R. Lardner ‘A Caddy’s Diary’ in Coll. Short Stories (1941) 396: Mr. Thomas was beat both in the A.M. and P.M. in spite of my help.
1939		W. Winchell On Broadway 8 Jan. [synd. col.] The primrose pathologists split their diagnoses, the ayem boys giving it ‘No sir’ and most of the peeyem lads agreeing [...] that it was ‘grand.’.
1939		Pittsburgh Courier (PA) 13 May 11/1: [She] tossed a broken glass at an ofay bar fly [...] the other ayem bercause he called her a n—lover .
1941		Pittsburgh Courier (PA) 3 May 7/2: You might find anybody there with anybody any time after twelve ayem.
1947		B. Schulberg Harder They Fall (1971) 131: Broadway in the a.m., caught up in the restless, over-stimulated going-and-coming.
1950		N. Cassady letter in Charters (1993) 200: We went to see his buddyboss next A.M.
1949		D. Burley N.Y. Amsterdam News 2 Apr. 33: .
1961		R.A. Norton Through Beatnik Eyeballs 84: Then, wham, I black out and lose the happenings till a.m. come.
1979		‘Iceberg Slim’ Airtight Willie and Me 25: Some ass-kicker was a cinch to be a ’ho short when the joints folded in the a.m.
1989		M. Walker How to Kiss a Crocodile 13: The story came from the manager of the Safari Lodge, Ray Alright, after a comforting, belly-warming, port or three in the early AM.
1989		M. Walker How to Kiss a Crocodile : .
1990		S. Morgan Homeboy 94: I’m callin Homicide in the ayem.
1999		Dr Dre ‘Still D.R.E.’ 🎵 Wake up in the A.M., compose a beat.
2011		J.J. Connolly Viva La Madness 195: Let us talk in the a.m.
2015		‘Harry Brandt’ Whites 1: One fifteen in the a.m.: tonight, as always, the calls could come in at any time.