Here's what rhymes with knack.
nach alk mac mak mack back lack pack rack sac sack hack jack tack fac lac shack smack snack tak whack wrack yak wack yack black attack track crack stack plaque slack aback flak quack unpack clack claque flack anorak maniac shellac ipecac repack thumbtack highjack mudpack almanac elegiac zodiac gunnysack rickrack skyjack cardiac paperback demoniac hardtack haversack lumberjack piggyback amnesiac razorback pickaback counterattack insomniac applejack crackerjack quarterback stickleback steeplejack nymphomaniac megalomaniac Words that almost rhyme with knack
ag mag nag bag lag tag rag gag hag wag fag sag snag zag dag shag flag drag slag stag brag crag swag blag toerag dishrag fleabag scrag washrag nosebag chinwag wigwag sleazebag lollygag lallygag saddlebag scalawag scallywag ask mask masque anc ankh bank task rank tank thank sank cask shank bask dank hanc lank talc hank yank basque blank drank flank flask frank crank plank shrank franc prank clank spank stank unmask swank embank outrank antitank riverbank databank pointblank charabanc