Green’s Dictionary of Slang

(US) a female prostitute or male homosexual who will not perform fellatio, i.e. will not eat v. (4) meat n.

1966		Trimble 5000 Adult Sex Words and Phrases.
1972		B. Rodgers Queens’ Vernacular 206: vegetarian man who does not suck cock, often said of trade.
1972		R.A. Wilson Playboy’s Book of Forbidden Words n.p.: Vegetarian. A whore who refuses French jobs.
1989		J. Morton Lowspeak.