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