Here's what rhymes with ubiquitarian.
carrion ovarian clarion agrarian librarian utilitarian barbarian egalitarian sectarian trinitarian cnidarian proletarian libertarian vegetarian sanitarian vulgarian authoritarian totalitarian antiquarian veterinarian octogenarian centenarian seminarian humanitarian communitarian disciplinarian nonsectarian nonagenarian sexagenarian parliamentarian latitudinarian septuagenarian valetudinarian Words that almost rhyme with ubiquitarian
barium chameleon vivarium aquarium honorarium nobelium sanitarium planetarium ferryman ferrymen lesbian thespian pedestrian vestrymen vestryman equestrian