a casual term for a very cool individual who is a friend of yours. used almost exclusively by the "skundy" subculture, along with words such as "rag" for cool, "mutge", pronounced moot-geh or moot-ger for the Brits, which means "dude", and "skundy", meaning cool or fashionable.
Nilly is a skundy term for nothing or very little. Synonyms include roberdank....just kidding.
"What's up homeboyt?"
"Nilly, mutge, nilly. You?"
"Just keepin it skundy."