Nefarious

//nɪˈfɛəɹi.əs// adj

adj ·Common ·High school level

Definitions

Adjective
  1. 1
    Sinful, villainous, criminal, or wicked, especially when noteworthy or notorious for such characteristics.

    "Aliens have a nefarious connotation in many science fiction books."

Adjective
  1. 1
    extremely wicked wordnet

Example

More examples

"There's nothing nefarious going on here."

Etymology

From Latin nefārius (“execrable, abominable”), from nefās (“something contrary to divine law, an impious deed, sin, crime”), from ne- (“not”) + fās (“the dictates of religion, divine law”), which is related to Latin for (“I speak, I say”) and cognate to Ancient Greek φημί (phēmí, “I say”).

Data sourced from Wiktionary, WordNet, CMU, and other open linguistic databases. Updated March 2026.