Green’s Dictionary of Slang

(US) a bartender.

1908		K. McGaffey Sorrows of a Show Girl Ch. x: Tell the barhop to mix me up a life preserver in a rose glass.
1930		M. Bodenheim Naked on Roller Skates 140: Slapped that barhop groggy down in Laredo, ’cause the ’hop was flipping his mouth about the bones being loaded.
2002		Tricia’s Time Out 🌐 Gee buddy, I sure do hate to ask you to go, but you got all these bums crying their eyes out again. But you come back. Maybe next time Tricia will be the barhop.