Definitions

1. noun

A knowledgeable and enthusiastic fan of jazz music, especially one who is well-versed in its history and terminology.

“The hepcat at the jazz club was able to explain the difference between bebop and swing to the newcomer.”

2. noun

A fashionable or stylish person, especially one who is knowledgeable about popular culture.

“The hepcat on the street corner was sporting the latest fashion trends from Paris.”