Here's what rhymes with quackish.
blackish brackish Words that almost rhyme with quackish
waggish haggish haggis parish lavish vanish banish radish hashish clannish mannish faddish famish raffish kaddish caddish palish laddish anguish catfish vanquish flattish snappish languish brandish flatfish blandish establish outlandish reestablish disestablish