Mammoth Uncensored Word List:
24 words ending with rm, 12 letters long

anguilliform biotransform campodeiform countercharm cylindriform endomesoderm epileptiform equisetiform fibrilliform flabelliform flagelliform hydatidiform lumbriciform morbilliform placentiform poikilotherm pteridosperm pulvilliform serpentiform stalactiform strobiliform thunderstorm trinacriform underperform