Leader, boss. A term mainly used to describe one stronger than oneself.
Grunt1: Before we decide to rob this bank, let's wait for my malefactor.

Grunt2: Nigger...
by Guy in the ATM line August 7, 2006
Synonym for "motherfucker" used on social media websites that discourage profanity.
That malefactor re-posted my joke as his own.
by bgparker October 5, 2010
One who spreads misery and maleficence. An unchivalrous, debased person with no sense of dignity or honor.
Knight 1: "Watch out for that neer-do-well. He has tried to lie to and to cheat us before."
Knight 2:"Is there no rest for a crestfallen malefactor?"
by slfr December 27, 2022