Mammoth Uncensored Word List:
25 words ending with py, 13 letters long

abdominoscopy actinotherapy balneotherapy bibliotherapy brachytherapy chromotherapy chronotherapy daguerreotypy diaphototropy esophagoscopy immunotherapy kinesitherapy musicotherapy omoplatoscopy organotherapy overpreoccupy parthenocarpy pharyngoscopy physiotherapy psychotherapy pyretotherapy sclerotherapy sigmoidoscopy speleotherapy thermotherapy