"Hep" has two slang meanings that I know of:
Hepatitis -- a blood disease which can have very severe effects. This is still current slang; we refer to "Hep A" and "Hep C" for example, when distinguishing between different kinds of hepatitis.
Hep, hepcat -- I think this slang began in the 1950s beatnik movement. It means being really cool, jazzy, hip -- as in, "That new club does poetry readings to the sound of bongo drums, it's really a hep place" or "Have you seen Don's new goatee? It really looks hep; he's such a hepcat." I don't think women were ever called hepcats.
In the 1920s? I'm not sure... It could be either or both of these, or something else altogether, but I hope this answer at least gives you a starting place.
Hepatitis -- a blood disease which can have very severe effects. This is still current slang; we refer to "Hep A" and "Hep C" for example, when distinguishing between different kinds of hepatitis.
Hep, hepcat -- I think this slang began in the 1950s beatnik movement. It means being really cool, jazzy, hip -- as in, "That new club does poetry readings to the sound of bongo drums, it's really a hep place" or "Have you seen Don's new goatee? It really looks hep; he's such a hepcat." I don't think women were ever called hepcats.
In the 1920s? I'm not sure... It could be either or both of these, or something else altogether, but I hope this answer at least gives you a starting place.