Here's what rhymes with costfunction.
function junction dysfunction disjunction injunction malfunction conjunction compunction Words that almost rhyme with costfunction
suction sunken drunken shrunken fuckin someone sudden deduction summon abduction seduction sullen sultan tungsten avulsion irruption subduction kuchen production construction discussion assumption destruction instruction reduction button corruption cousin dozen induction conduction obstruction disruption eruption dungeon emulsion luncheon mutton percussion muslin perdition revulsion huntsman yeomen bludgeon gulden gunman muffin coven dudgeon gumption liposuction toughen bunion dustpan lumpen mullion piton roughen scullion scutcheon dustman nubbin biathlon dubbin presumption compulsion expulsion interruption repulsion resumption convulsion propulsion transduction exciton globin escutcheon glutton impulsion decagon stuntman grunion consumption introduction reconstruction reproduction combustion androgen concussion deconstruction overproduction repercussion unbutton caparison semicolon misconstruction ragamuffin underproduction bellybutton reintroduction