Green’s Dictionary of Slang

(orig. US black teen) the scrotum, the penis.

1987		EPMD in Adler Rap! 67: Grab my bozack.
1991		Tribe Called Quest ‘Check the Rhime’ 🎵 The rhymes were so rumpin that the brothers rode the ’zack.
1994		EPMD ‘Mr Bozack’ 🎵 Good morning Mr. Bozack time to wake up the nuts / (For what) to hit the shower so I can wash the butt.
c.2000		UNLV ‘Tec-9 What Ya Like’ 🎵 I like a bitch who ain’t afraid to suck the bozack.
2002		‘Touré’ Portable Promised Land (ms.) 156: We Words (My Favorite Things) [...] Bogart. Bozack. Buster.
2006		Urban Dict. 🌐 Bozack. Your johnson, your peter, your cock and balls. Well maybe minus the balls.