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