Fiendish

//ˈfiːndɪʃ// adj

adj ·Moderate ·College level

Definitions

Adjective
  1. 1
    Sinister; evil; like a fiend.

    "The detective was puzzled by the fiendish plot to steal the diamonds."

  2. 2
    Very difficult.

    "The exam was filled with fiendish questions that made no sense."

Adjective
  1. 1
    extremely evil or cruel; expressive of cruelty or befitting hell wordnet

Example

More examples

"Somewhere there, on that desolate plain, was lurking this fiendish man, hiding in a burrow like a wild beast, his heart full of malignancy against the whole race which had cast him out. It needed but this to complete the grim suggestiveness of the barren waste, the chilling wind, and the darkling sky."

Etymology

From fiend + -ish.

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