ne·far·i·ous
/nəˈferēəs/
adjective
adjective: nefarious
(typically of an action or activity) wicked or criminal.
"the nefarious activities of the organized-crime syndicates"
synonyms: wicked, evil, sinful, iniquitous, egregious, heinous, atrocious, vile, foul, abominable, odious, depraved, monstrous, fiendish, diabolical, unspeakable, despicable; More
villainous, criminal, corrupt, illegal, unlawful;
dateddastardly
"the nefarious long-lost brother returns to steal Iris's inheritance"
antonyms: good