Green’s Dictionary of Slang

1. (US) goings-on, esp. those of an intimate nature.

1953		L. Durst Jives of Dr. Hepcat (1989) 1: In spinning a platter of some very popular band leader, I would come on something like this: ‘Jackson, here’s that man again, cool, calm and a solid wig, he is laying a frantic scream that will strictly pad your skull, fall in and dig the happenings.’ Which is to say, the orchestra leader is a real classy singer and has a voice that most people would like.
1956		‘Hal Ellson’ ‘Dangerous’ in Tell Them Nothing (1956) 49: My special friend Julie comes in and greets me. I give him the happenings.
1965		(con. 1940s) Malcolm X Autobiog. (1968) 140: Cats who were hip to all happenings.
1972		J. Maryland ‘Shoe-shine on 63rd’ in Kochman Rappin’ and Stylin’ Out 211: Pretty Black, grinning and checking the crowd to be sure everyone was hip to the happenings.
1980		E. Folb Runnin’ Down Some Lines xvii: They hip to some o’ d’ hap’nins, they blood.
1994		N. McCall Makes Me Wanna Holler (1995) 138: Let’s go, man. There’s no happ’nin’s here.
2013		W.D. Myers Cruisers: Oh, Snap! 17: I was the only one back there who didn’t know where the happenings were.

2. (US drugs) any illicit narcotics.

1958

M.A. Crane ‘Misc.’ in AS XXXIII:3 225: junk, gage, happenings, pod, and tea (all meaning narcotics).

3. (US black) in fig. use, women.

1957

H. Simmons Corner Boy 147: Pick up on the happenings. They’re ready to go, drunk as hell.