Mammoth Uncensored Word List:
28 - 16 letter words starting with l

lactovegetarians lamentablenesses landlubberliness laparoendoscopic laparoscopically largeheartedness lasciviousnesses latensifications leptogeosyncline leukodystrophies libidinousnesses licentiousnesses lightheartedness lighthousekeeper lightstimulation lithocystotomies lithographically lithoheterotroph liverheartedness localizabilities longheadednesses loquaciousnesses lugubriousnesses luposlipaphobics lymphangiectasia lymphangiography lymphangiomatous lymphogranulomas