Fiendish/ˈfiːndɪʃ/ Definition 1 of 2Pro Tip 1/3Negative Connotation Fiendish as cruel has a strong negative tone, suggesting inhuman malice or guilt. The villain's fiendish laugh echoed in the silence. Pro Tip 2/3Vivid Imagery Use 'fiendish' to invoke strong, dark mental images, supporting a suspenseful mood. Her fiendish smile forewarned of the impending betrayal. Pro Tip 3/3Intensity Amplifier 'Fiendish' elevates the intensity of cruelty to extreme levels, often in storytelling. He concocted a fiendish scheme to overthrow the kingdom.