12 letters
- nymphomanias27
- octapeptides22
- oleandomycin24
- omnipotences23
- omnipotently23
- omnisciently23
- onomastician20
- opalescently23
- openhandedly24
- operationism19
- operationist16
- opposability24
- oppositional20
- optimalities19
- optimisation19
- orientations14
- ornamentally21
- osmolalities17
- osteomalacia19
- osteopathies17
- outlandishly21
- palatability22
- palatialness18
- palindromist21
- palpitations20
- palynologies22
- palynologist22
- pancytopenia25
- pantothenate19
- paratyphoids23
- passionately19
- pathetically24
- pectinations20
- pedantically24
- pedestalling21
- penalization27
- penetrations17
- penitentiary19
- pennywhistle25
- pentagonally23
- pentahedrons20
- pentamidines21
- pentlandites19
- periodontist17
- peritoneally20
- pestilential18
- phanerophyte25
- phenomenally26
- phenotypical27
- phentolamine23
- philadelphus26
- philanthropy26
- philatelists19
- phillumenist24
- philosophies23
- philosophise23
- philosophize32
- phlebotomies24
- phlebotomist24
- phonemically28
- phonetically25
- phoneticians22
- phosphatides23
- phosphatidic26
- phosphatidyl26
- phosphatized32
- phospholipid27
- photochemist25
- photodynamic27
- photometries20
- phreatophyte24
- phyllotaxies28
- phytoalexins28
- phytochemist27
- pigmentation22
- pinealectomy25
- piroplasmata22
- placentation21
- plainclothes23
- planetesimal21
- plastocyanin23
- platitudinal20
- pleiotropies19
- podophyllins26
- podophyllums29
- pollinations19
- polyglottism24
- polypeptides25
- polypetalous23
- polyphenolic28
- polyploidies23
- polysyndeton23
- polytheistic23
- polytonality22
- populational22
- positionally20
- postdeadline19
- postelection20
- posthospital21
- posthypnotic26
- postimperial22
- postmedieval24
- postmidnight24
- postneonatal18
- postponement23
- postprandial21
- potentiality19
- potentiation17
- prednisolone19
- predominates20
- prehensility21
- premonitions20
- prenominated21
- prenominates20
- presentation17
- presidential18
- pronominally24
- prothalamion22
- protonematal20
- protoplanets20
- pteridophyte23
- rationalised15
- reanimations17
- relationship19
- remediations17
- repetitional17
- replantation18
- repositioned17
- retaliations14
- salamandrine19
- salutational16
- scintillated19
- segmentation19
- semantically23
- semiannually22
- semicolonial21
- semidominant21
- semipalmated23
- sempiternity21
- septennially21
- simoniacally23
- simultaneity20
- siphonostele19
- speciational20
- spheroidally22
- splenomegaly25
- stapedectomy24
- staphylinids22
- stenothermal19
- stichomythia24
- stonyhearted18
- strophanthin21
- supplemental25
- synaptosomal22
- tangentially20
- taphonomists21
- technophiles24
- telephonists19
- tendonitises15
- terminations17
- tessellation15
- testimonials17
- tetrahymenas20
- thalidomides20
- thallophytes23
- thallophytic26
- theistically21
- thematically24
- theophylline24
- theosophical23
- thermohaline21
- thermophiles23
- thiocyanates20
- titleholders17
- toxophilites25
- trampolinist20
- transitional15
- transplanted19
- trepanations17
- trephination19
- trepidations17
- triphosphate22
- tripinnately20
- tryptophanes23
- unhandsomely24
- unhealthiest19
- unhyphenated25
- unmyelinated22
- unpleasantly22
- vasodilation19
- ventilations19
- wollastonite18
- xanthophylls31