Here's what rhymes with rigidum.
Words that almost rhyme with rigidum
sudden button dudgeon erratum piton dubbin mutton bludgeon nubbin exciton globin escutcheon glutton unbutton scutcheon androgen bellybutton dumdum buxom caecum buncombe bunkum custom secundum humdrum jejunum corundum accustom cementum conundrum carborundum colostrum