Green’s Dictionary of Slang

macker n.2

[mack n.2 (1)]

(US Und.) a pimp.

[US]N. Algren ‘Watch Out for Daddy’ in Entrapment (2009) 121: I make as sorry a whore as you make a macker.
[US]N. Algren Walk on the Wild Side 197: Let’s see what them damn mackers are up to.