The adjective fiendish means cruel, wicked, and evil. It often describes things that are not supposed to be alive, like monsters.

  • The creature was so fiendish that even the bravest of men was afraid to approach it.

  • The fiendish witch was able to cast spells that made people sick.

Definition of fiendish


extremely evil or cruel; expressive of cruelty or befitting hell


demonic, diabolic, diabolical, hellish, infernal, satanic, unholy

Nearby Words

fiendish Pronunciation in a video

Example Sentences for fiendish

  • 1

    I know of your fiendish plans.

  • 2

    He transforms into a fiendish demon dragon.

  • 3

    This provides the sort of tense and fiendish gameplay.

  • 4

    Can they be allowed to continue their fiendish reign of terror

  • 5

    He is not a perfidious or barbarous or fantastically fiendish foe.

  • 6

    Halloween's fiendish fun translates into big bucks.

  • 7

    Most people might not be aware of is his fiendish love.

  • 8

    I had been duped by fiendish studio producers.

  • 9

    This halloween bash is perfect for inviting your fiendish friends.

  • 10

    He then chuckles at seeing the girl's fiendish gleam in her eyes.