Mammoth Uncensored Word List:
15 words ending with l, 20 letters long

acetylmethylcarbinol archaeometallurgical chemicophysiological electrometallurgical electrophysiological micropaleontological neuropharmacological paleoanthropological pericardicperitoneal pericardioperitoneal phosphatidylinositol psychopharmaceutical semiautobiographical spectrophotometrical tetrahydrocannabinol