13 letters
- herringboning25
- heterocyclics27
- heterocystous21
- heterogametes20
- heterogametic23
- heterogeneity20
- heterogeneous19
- heterokaryons22
- heteromorphic26
- heterophonies21
- heteropterous19
- heterosexuals24
- heterospories18
- heterosporous19
- heterothallic22
- heterotrophic23
- heterozygoses28
- heterozygosis28
- heterozygotes28
- heuristically23
- hexamethonium32
- hexobarbitals29
- histochemical27
- homeothermies23
- homestretches23
- homoiothermic26
- horsefeathers20
- horseradishes18
- hotheadedness20
- hydrographers25
- hyperesthesia22
- hyperesthetic25
- hyperthermias25
- hypothecating28
- hypothecation26
- hypothecators25
- hypothesizing34
- iconographers24
- immunochemist29
- immunotherapy28
- impoverishers25
- inheritresses16
- intrathecally23
- kindheartedly25
- knuckleheaded31
- leatherleaves21
- lecherousness21
- lexicographer31
- lichenologies23
- lichenologist23
- lithographers23
- luncheonettes22
- magnetosphere24
- mantelshelves25
- mathematician25
- mathematizing33
- mesotheliomas22
- methemoglobin28
- microswitches27
- misapprehends26
- monomorphemic31
- morphemically31
- motherfuckers29
- motherfucking32
- multibranched28
- mythographers27
- nephelometers23
- nephelometric26
- neurasthenias18
- neurasthenics21
- neurochemical27
- neurochemists23
- nonhereditary20
- nontheatrical21
- normothermias22
- northeasterly19
- northeastward20
- oceanographer24
- openheartedly23
- openmouthedly27
- orchestraters18
- orchestrating21
- orchestration19
- orchestrators18
- overlengthens24
- overnourished22
- overnourishes21
- overstretched23
- overstretches22
- oxyhemoglobin34
- oystercatcher23
- paleographers24
- pantheistical23
- pantothenates20
- paraesthesias18
- paraphernalia23
- parasyntheses21
- parasynthesis21
- parasynthetic24
- parenthesized29
- parenthesizes28
- parenthetical23
- parthenocarpy27
- perphenazines32
- petrochemical28
- petrographers23
- phenanthrenes23
- phencyclidine30
- phenmetrazine32
- phenobarbital26
- phenomenalism27
- phenomenalist24
- phenomenology28
- phenothiazine31
- phentolamines24
- phenylalanine25
- phenylephrine28
- philhellenism27
- philhellenist24
- phonographers26
- photochemical30
- photochemists26
- photofinisher24
- photographers25
- physiographer27
- physiotherapy27
- phytochemical32
- phytochemists28
- pigheadedness23
- pinheadedness22
- platyhelminth28
- poikilotherms26
- polycythemias29
- pornographers24
- preanesthetic22
- prescheduling27
- procathedrals23
- prophetically28
- propoxyphenes34
- psychasthenia26
- psychasthenic29
- psychotherapy30
- pyrheliometer24
- rabbitbrushes25
- radiochemical26
- radiochemists22
- rapprochement28
- reestablished20
- reestablishes19
- reorchestrate18
- reprehensible23
- reprehensibly25
- reprehensions20
- reprographers23
- restrengthens19
- resynthesized28
- resynthesizes27
- rheologically25
- rheumatically26
- rhombohedrons25
- rutherfordium24
- scenographers24
- schematically28
- schoolteacher24
- seismographer23
- semisynthetic24
- sheepherdings24
- sheepshearers20
- sheepshearing23
- shellcrackers27
- shepherdesses21
- softheartedly22
- southeasterly19
- southeastward20
- southernwoods21
- spaghettilike25
- spirochetoses21
- spirochetosis21
- staggerbushes23
- steeplebushes23
- stenographers21
- stereographed21
- stratospheres18
- stratospheric21
- strengtheners19
- strengthening22
- superchurches28
- superencipher26
- superheroines20
- surgeonfishes22
- sympathectomy31
- synaesthesias18
- synchromeshes26
- synthetically25
- telegrapheses21
- tenderhearted18
- tetartohedral17
- tetrahedrally20
- tetrahedrites16
- theatergoings20