Mammoth Uncensored Word List:
25 - 17 letter words starting with l

lamellibranchiate laryngopharyngeal laryngotracheitis latitudinarianism lepidopterologies lepidopterologist leptogeosynclinal leptogeosynclines levelheadednesses lexicographically lightfingeredness lighthousekeepers lithoheterotrophs lithoheterotrophy lithostratigraphy longsightednesses lumpenproletariat lymphadenectomies lymphadenopathies lymphangiographic lymphangiosarcoma lymphoepithelioma lymphogranulomata lymphoreticulosis lymphoscintigraph