Green’s Dictionary of Slang

(US black teen) an imitation of the sound of gunfire.

1995

Bone Thugs-N-Harmony ‘Mo’ Murda’ 🎵 on E. 1999 Eternal [album] If you wanna die bye, / See you in the gutter let mama cry, / Watch Mo Thug Killas pump pump, / Put ’em in the ground with his head blown gone / Mo murda, mo murda, mo murda.