Green’s Dictionary of Slang

1. one who pursues prostitutes [punk n.¹ (1)].

1675		C. Cotton Scoffer Scoff’d (1765) 253: He is a very honest Younker / A bonny Lad, and a great Punker.
1736		J. Addison (trans.) Petronius Arbiter 87: He was a great Punker, and nothing that wore a Cap came amiss to him [OED].

2. (US prison) a male homosexual who takes the active role in anal intercourse [punk n.¹ (5)].

1972

B. Rodgers Queens’ Vernacular 18: The man who fucks in anal intercourse, as opposed to the one who is fucked [...] punker (prison sl).