Definition of "black man"
noun
countable and uncountable, plural black men
(now rare) An evil spirit, the bogeyman, a demon.
Quotations
[H]e suspects everything he hears and sees to be a devil, or enchanted, and imagineth a thousand chimeras and visions, which to his thinking he certainly sees, bugbears, talks with black men, ghosts, goblins, etc.
1624, Robert Burton, The Anatomy of Melancholy, volume I, New York Review Books, published 2001, page 387