Green’s Dictionary of Slang

1. (US) a lesbian.

1962		D. Maurer in Mencken Amer. Lang. (1963) 728: The bull bitch or butch pimp [is] a lesbian who has one or more girls and services them like a man.
1972		B. Rodgers Queens’ Vernacular 38: bull-dagger [...] Syn: bull bitch [dyke].
1989		H. Rawson Dict. of Invective (1991) 45: Common current forms include [...] bull bitch (a woman with masculine traits).
2000		F.X. Toole Rope Burns 83: ‘What if the ref sees me?’ ‘Keep the bull bitch between you and him and he won’t.’.

2. (US) a hermaphrodite.

1987

in Murray & Murrell Lang. Sadomasochism (1989) 46: Genuine bull bitches are rare, but they’re in super hot demand by the blue video industry.