BTW: Doesn't "Nut Up" refer to ejactulation?

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Some Common Slang

Gang banger: an active gang member.
Home boy or home girl: gang member.
Jump in: gang initiation.
Nut up: angry.
OG: original gang member.
Packing: gang member with a gun.
Shooter: a gang member who uses a gun.
Tagger: someone who uses graffiti.
Wannabe: youngster who wants to be a gang member.