nefarious (adj.) Look up nefarious at Dictionary.com
c. 1600, from Latin nefarius "wicked, abominable, impious," from nefas "crime, wrong, impiety," from ne- "not" (see un- (1)) + fas "right, lawful, divinely spoken," related to fari "to speak," from PIE root *bha- (2) "to speak, tell, say" (see fame (n.)). Related: Nefariously.