hepster, n. — Green’s Dictionary of Slang

hepster n.

1. a swing musican.

1947

N. Slonimsky Road to Music 160: Hepster is, of course, no misprint for Webster, but a hep cat, ie, a swing musician.

2. a jazz or swing fan.

1941		‘Digg Mee’ ‘Observation Post’ in N.Y. Age 12 Apr. 9/6: For the ‘square’ and ‘hepster’ too, all my jive is just for you.
1953		L. Durst Jives of Dr. Hepcat (1989) 1: For instance, there was a jam session of topnotch musicians and everything was jumping and you would like to explain it to a hepster.
1999		(con. 1940s) Susan J. Douglas Listening in: Radio and the Amer. Imagination 235: He then introduces a ‘hepster with the hottest licorice stick in town.’.

3. attrib. use of sense 2.

2004

M. Foreman & M.A. Neal That’s the Joint! 97: In some ways today it operates much like early hepster phraseology.