Green’s Dictionary of Slang

(US black) saying inappropriate, tactless things, acting insanely.

1988		EPMD ‘I’m Housin’’ 🎵 on Strictly Business [album] As I proceed to rock, the girls are clockin.
1994		C. Major Juba to Jive 100: Clocking; clocking out v. (1980s–1990s) to say inappropriate, malicious things; also, to be mentally disturbed; to do ‘crazy’ things.