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