RhymeZone: hepcat definitions

Definitions of hepcat:

noun: (informal, music) A jazz performer, especially one from the 1940s and 1950s.
noun: (informal, dated, now often humorous) A person associated with the jazz subculture of the 1940s and 1950s.
noun: (informal, dated) A sophisticated person, one who is stylish.

(Definitions from Wiktionary)