Green’s Dictionary of Slang

smartly, fashionably.

1962		(con. 1953–7) L. Yablonsky Violent Gang (1967) 66: They both spoke very ‘hip’, and greeted Duke: ‘Hello, Duke daddy – what’s shakin’? Who’s this cat?’.
1999		‘Master Pimp’ Pimp’s Rap 177: Everyone wants to feel important. That’s why niggers dress hip, why Whitey wants to rule.