12 letters

levalbuterol levalloisian levallorphan levansucrase levarterenol levisomnious levitational ∙ leviticalism leviticality levoaurality levocularity levofloxacin levolimonene levorotation levorotatory ∙ levotartaric levulosaemia lexicalising ∙ lexicalities ∙ lexicalizing ∙ lexicography ∙ lexicologies ∙ lexicologist ∙ lexigraphies ∙ Lexovisaurus

13 letters

leadenhearted learnednesses ∙ leatherfishes leatherflower leatherjacket ∙ leatherleaves ∙ leathermaking leatherworker lecanoraceous lecherousness ∙ lecithalbumin lectisternium ∙ Lecythidaceae legalisations ∙ legalizations ∙ leggierissimo Leghemoglobin legiblenesses ∙ legionellosis legislational legislatively ∙ legislatorial ∙ legislatrices legislatrixes legitimations ∙ legitimatised ∙ legitimatises ∙ legitimatized ∙ legitimatizes ∙ leglessnesses ∙ leiocephalous leiodermatous leiomyomatous leiotrichidae leiotrichinae leishmaniases ∙ leishmaniasis ∙ leishmanioses ∙ leishmaniosis ∙ leisureliness ∙ leitneriaceae lemmatisation ∙ lemmatization ∙ lendrumbilate lengthinesses ∙ lenticulating lenticulation lentitudinous leontopodiums ∙ lepidoblastic Lepidocrocite lepidodendrid lepidodendron Lepidodendrum lepidomelanes ∙ lepidophloios lepidophyllum lepidopterans ∙ lepidopterist ∙ lepidopterons ∙ lepidopterous ∙ lepidosaurian lepidospermae lepidostrobus Lepidothamnus lepisosteidae leposternidae leprechaunish ∙ leprechaunism leprousnesses ∙ leptocephalan leptocephalia leptocephalic ∙ leptocephalid leptocephalus ∙ Leptoceratops leptochlorite leptodactylus leptokurtosis leptomeninges leptonecrosis leptophyllous ∙ leptoprosopia leptoprosopic leptorrhinian leptorrhinism leptosphaeria leptospiroses ∙ leptospirosis ∙ leptospiruria leptostracous leptotyphlops Lesothosaurus lethargically ∙ lethargogenic letterboxings ∙ letterpresses ∙ Letterspacing ∙ leucaemogenic ∙ leucaethiopes leucaethiopic leucitohedron ∙ leuckartiidae leucobryaceae leucochalcite leucocythemia leucocythemic leucocytology leucocytozoon leucodepleted ∙ leucomelanous leucophyllous leucoplastids ∙ leucospermous leucosphenite leuenkephalin leukapheresis leukoaraiosis leukochloroma leukocytactic leukocythemia leukokinetics leukomyelitis leukonecrosis leukoprotease leurocristine levelheadedly levetiracetam leviticalness levobetaxolol levocabastine levocarnitine levoclination levothyroxine lexicographer ∙ lexicographic ∙ lexicological ∙ lexicologists ∙ lexigraphical ∙ lexiphanicism

14 letters

leachabilities ∙ Leaellynasaura leaflessnesses ∙ learnabilities ∙ leatherinesses ∙ leatherjackets ∙ leatherworking lechatelierite lecithoprotein lecythidaceous ∙ legalistically ∙ legerdemainist ∙ leghaemoglobin legislatorship ∙ legislatresses ∙ legitimateness ∙ legitimatising ∙ legitimatizing ∙ legitimisation ∙ legitimization ∙ leguminivorous leibnitzianism Leicestershire leiomyofibroma leiomyomatosis leiomyomectomy leiomyosarcoma Leipsanosaurus leitneriaceous lemaireocereus lemmatisations ∙ lemmatizations ∙ lengthsomeness lenticulooptic lepidodendrids lepidodendroid ∙ lepidodentroid Lepidoganoidei lepidophyllous lepidopterists ∙ lepidosirenoid Lepidotrichium Leporipoxvirus lepospondylous leptinotarsins leptocephaloid leptocephalous ∙ leptochromatic leptodactylous ∙ leptodermatous leptomeningeal leptoprosopous leptothricosis leptotrichosis letterspacings ∙ Leuchtenbergia leucitohedrons ∙ leucocythaemia ∙ leucocythaemic leucocytoblast leucocytolyses ∙ leucocytolysin leucocytolysis ∙ leucocytolytic leucocytometer leucocytopenia ∙ leucocytopenic leucocytotaxia leucocytotaxis leucodermatous leucoindigotin leucophlegmacy leukemogeneses ∙ leukemogenesis ∙ leukoblastosis leukocytoblast leukocytolysin leukocytolysis leukocytolytic leukocytometer leukocytopenia leukocytophagy leukocytotaxia leukocytotaxis leukocytotoxin leukodermatous leukodystrophy ∙ leukokeratosis leukokraurosis Leukoreduction levocardiogram levonorgestrel lexicalisation ∙ lexicalization ∙ lexicographers ∙ lexicographian lexicographies ∙ lexicographist ∙

15 letters

leatherlikeness leatherstocking lecherousnesses ∙ lecithovitellin legerdemainists ∙ legislatorially legislatorships ∙ legitimisations ∙ legitimizations ∙ leisurelinesses ∙ leontocephalous lepidodendroids ∙ lepidoporphyrin lepidopterology ∙ lepidosirenidae leptocephalidae leptodactylidae leptomeningitis leptomorphology Leptotrombidium lethargicalness leuchtenbergite leucocythaemias ∙ leucocytopenias ∙ leucocytoplania leucophoenicite leucoquinizarin leucosoleniidae leukaemogeneses ∙ leukaemogenesis ∙ leukoagglutinin leukocytoclasis leukocytoplania leukocytotactic leukodystrophia leukomyelopathy leukoriboflavin leukosulfakinin levelheadedness ∙ levobupivacaine lexicalisations ∙ lexicalizations ∙ lexicographical ∙ lexicographists ∙ lexicologically ∙ lexiconophilist lexicostatistic lexigraphically

16 letters

legitimatization Lentibulariaceae lenticulopapular lenticulostriate lepidodendraceae lepidopterophily leptosporangiate Leptotyphlopidae leucocytogenesis leucocytopoiesis leucocytotherapy leukocytogenesis leukocytopoiesis levocycleduction levocycloduction lexicostatistics

17 letters

leadenheartedness legantinelegatary lentibulariaceous lenticulothalamic lepidodendraceous lepidopterologist leptomeningopathy leptonomorphology leptostromataceae leucoencephalitis leukoencephalitis leukophagocytosis lexicographically lexicostatistical

18 letters

lepidopterological lepidopterophilist lepidopterophilous Leukencephalopathy

19 letters

leukoencephalopathy

21 letters

Leistungsgemeinschaft leukoencephalomalacia leukoerythroblastosis

Words with a ∙ are valid Scrabble words (SOWPODS word list)