Nigga refers to person who is yo friend or homie
Person: Yo what's up my nigga
Nigga: Not much homie
"nigga" is an insulting term for a dark skinned person, but can also be meant in a friendly way.
"can i borrow your french fry, nigga"
"wanna go to my house after this, my nigga?"
"nigga, please"
"bitch ass nigga"
A black person that does drugs or some illegal stuff
Look! That nigga does drugs. He should go to jail.
"Nigga" is a slur for black people. Often referred as the N-Word or N-Slur. Shouldn't be used in a sentence. If you see someone use it, they are probably racist.
Person 1: "Hey man, remember that nigga from the-"
Person 2: "Did you just say the N-Slur? You're racist!"