17 letters
- nonestablishments29
- nonreappointments30
- nonrepresentative27
- overconcentration30
- overconscientious30
- overembellishment35
- paleoanthropology32
- pentachlorophenol34
- pentylenetetrazol35
- philanthropically36
- photodisintegrate26
- photointerpreters26
- photosynthesizing39
- pithecanthropines32
- plenipotentiaries26
- precipitantnesses28
- presentablenesses26
- pretentiousnesses23
- quadricentennials35
- quatercentenaries32
- recentralizations32
- recontextualizing42
- reinterpretations22
- roentgenographies28
- rudimentarinesses24
- semidocumentaries29
- sententiousnesses21
- sesquicentenaries32
- sesquicentennials34
- spontaneousnesses24
- substantialnesses24
- substantivenesses27
- superintellectual29
- superintelligence30
- superintendencies28
- superromanticisms31
- tendentiousnesses22
- thermoluminescent32
- tintinnabulations26
- transcendentalism28
- transcendentalist25
- transparentnesses23
- transplantability29
- transubstantiated24
- transubstantiates23
- ultracentrifuging32
- ultracontemporary31
- uncontrollability31
- uncontroversially31
- unconventionality32
- underachievements33
- underdevelopments33
- undernourishments28
- unintelligibility30
- unpretentiousness25
- untranslatability27
- venturesomenesses27
- warrantablenesses26