Mammoth Uncensored Word List:
34 words ending with py, 11 letters long

arthroscopy chronoscopy coelioscopy colonoscopy cranioscopy cryotherapy electrotypy enteroscopy fluoroscopy gastroscopy glottiscopy hemotherapy hepatoscopy hydatoscopy keratoscopy laparoscopy lycanthropy metoposcopy microfloppy misanthropy morphotropy nephroscopy oneiroscopy pelotherapy proctoscopy psychoscopy retinoscopy serotherapy stereoscopy stethoscopy stroboscopy theanthropy trichoscopy vapotherapy