Mammoth Uncensored Word List:
30 words ending with my, 14 letters long

appendicectomy appendicostomy astragalectomy cholecystecomy cholecystotomy cholelithotomy clitoridectomy commissurotomy cricothyrotomy encephalectomy endarterectomy ganglionectomy hemipelvectomy hypophysectomy lithocystotomy mandibulectomy mediastinotomy pancreatectomy panniculectomy pericardiotomy postcraniotomy postmastectomy pyelolithotomy quadrantectomy radioastronomy sphincterotomy synchondrotomy thyrocricotomy trabeculectomy ultramicrotomy