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