Definition of "hepcat"

Everybody is asking, Why is Harry such a solid sender? Well, hear my version. As you are seated or are trying to stay seated you feel that sensation that hits every hep-cat. First your feet get the sensation, then it runs up your leg and you start to keep time to the music with your feet and you feel like getting up and jiving to that fine music that comes out of the magic trumpet of Harry James.

1943 May 9, Orlando Suero, “Jive, as a Hep-Cat Hears it”, in The New York Times‎

Leaders of the eight or nine name dance bands, who can throw a cordon of jitterbugging youths around any big city's theatre on a half hour's notice, are not complaining aloud these days, but privately they admit that “government competition” is having a lot to do with their ability to get it hot or sweet to suit the mood of the hepcats.

1943 June 20, John Desmond, “Making Catnip for the Hepcats”, in The New York Times‎

Finally the door opens and out comes Alex Aums in a sharp blue suit, like a hepcat, cigarette in mouth, squinting at us narrow-eyed, “O there you are,” to me, “how’ve you been? Wont[sic] you come in?” indicating the office.

1965, Jack Kerouac, Desolation Angels, page 177

Today he’s just a sleazy oldster, but in the beginning he was a faux philosopher, preaching a gospel cribbed from bohemia and various Freudian enemies of repression, in which the blessed pursuit of promiscuity was the human birthright. But really a male birthright, for a certain kind of man: The sort of hep cat who loved inviting the ladies back to his pad “for a quiet discussion on Picasso, Nietzsche, jazz, sex.”

2016 August 14, Ross Douthat, “A Playboy for President”, in The New York Times‎