Mammoth Uncensored Word List:
21 - 15 letter words starting with le

leatherstocking leatherworkings lecherousnesses legerdemainists legislatorships legitimisations legitimizations leiomyosarcomas leisurelinesses lepidodendroids lepidopterology leucocythaemias leucocytopenias leukaemogeneses leukaemogenesis levelheadedness lexicalisations lexicalizations lexicographical lexicographists lexicologically