Green’s Dictionary of Slang

1. (US) a blackjack, a club.

1927

(con. 1890s) H. Asbury Gangs of N.Y. 283: Many of the gangsters kept reserve revolvers and blackjacks, which they called Bessies, in cigar and stationery stores throughout their districts.

2. (US gay) a male homosexual, esp. when used as a term of address.

1972

R.A. Wilson Playboy’s Book of Forbidden Words.