15 letters
- nonspecifically33
- nonstationaries18
- nontotalitarian19
- nontransferable25
- nonuniformities25
- nonuniquenesses30
- nonuniversities23
- nonutilitarians20
- norepinephrines26
- normativenesses24
- notwithstanding26
- novemdecillions30
- obnoxiousnesses28
- oceanographical30
- organochlorines25
- organomercurial26
- organometallics26
- organophosphate28
- palynologically32
- paranormalities23
- parthenocarpies27
- parthenogeneses24
- parthenogenesis24
- parthenogenetic27
- pharmacognosies29
- pharmacognostic32
- phenobarbitones28
- phenolphthalein31
- phenomenalistic29
- phenomenologies28
- phenomenologist28
- phonocardiogram30
- phonogramically33
- pinocytotically31
- platinocyanides27
- platitudinously26
- postinoculation25
- precipitinogens28
- prenotification26
- prognosticating27
- prognostication25
- prognosticative28
- prognosticators24
- pulchritudinous29
- renormalization30
- retinoblastomas23
- roentgenography28
- roentgenologies22
- roentgenologist22
- semipornography31
- stratovolcanoes24
- superphenomenon30
- synchronousness26
- technologically31
- technostructure26
- tenosynovitises23
- teratocarcinoma25
- trigonometrical25
- trypanosomiases24
- trypanosomiasis24
- tyrannosauruses21
- ultrasonography27
- unchronological30
- unknowabilities29
- unknowledgeable33
- unobjectionable37
- unobtrusiveness26
- unpronounceable30
- vicissitudinous26