Fiendish rhymes with:
brandish, cavendish, outlandish, standish, windisch, windish, bowdish, bradish, brandish, cavendish, childish, faddish, gladish, horseradish, kadish, kurdish, outlandish, prudish, radish, reddish, redish, standish, swedish, windisch, windish, yiddish
Fiendish sounds like:
fanatic, fanatics, fantasia, fantasies, fantasize, fantasizes, fantasy, fantozzi, fends, fiends, finds, fonda's, fondues, fontes, fonts, fuentes, fuentez, fund's, funds, funds'