nefariousness

adjective

1. extremely wicked or villainous; iniquitous: a nefarious plot.

adjective

1. evil; wicked; sinful

adj.c.1600, from Latin nefarius “wicked, abominable, impious,” from nefas “crime, wrong, impiety,” from ne- “not” (see un-) + fas “right, lawful, divinely spoken,” related to fari “to speak” (see fame (n.)). Related: Nefariously.