1. A large blunt instrument one uses to quell the aggressions of violent niggas.
2. The words uttered by the person immediately after brandishing said blunt instrument.
3. The words uttered by a nigga immediately after such an instrument is produced.
The cop snapped out his retractable baton and faced the perp.
"Nigga be cool"

"Ay Vern, I think I left my lead pipe in yo' car."
"Oh you mean the nigga-be-cool stick? Yeah I got it."
by MossbergPump August 31, 2006
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A slap to calm you or your friend down when out of control
You better chill before I Nigga be cool slap you!
by Solja Loki February 12, 2009
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