A word used by ignorant white people to offend Black people inadvertantly (because sometimes they are just grasping at straws for a reason to feel oppressed, not all the time, just sometimes) because the white person really didn't know what it meant and just happened to ask her black friend, because she also happens to be her coolest friend, the one most familiar with slang. I would have asked a person of any race were that person better connected than Gaia with american vernacular, but she is the best I know.
Me "Gaia, what's nappy?"
Gaia puts her head in her hands and sighs, groans and then is silent.
Gaia "I'm so tired of you coming to me just because I'm your only Black friend"