15 letters
- optoelectronics26
- orchestrational22
- orthopsychiatry29
- overabstracting28
- overcentralized34
- overcentralizes33
- overconstructed28
- overcontrolling28
- overextractions30
- overextravagant33
- overorchestrate24
- oxytetracycline34
- parametrization31
- penetrabilities23
- photoautotrophs26
- photoelectronic28
- photogrammetric31
- photometrically30
- phototropically30
- planimetrically30
- polyelectrolyte28
- posttransfusion24
- preregistration21
- psychiatrically32
- psychometrician32
- pyroelectricity29
- radiometrically26
- radiostrontiums21
- radiotelemetric23
- recalcitrancies26
- reconcentrating26
- reconcentration24
- reconstructible27
- reconstructions24
- redistributions21
- reflectometries25
- refractometries24
- reindustrialize28
- reintroductions22
- remonstratively26
- reorchestrating23
- reorchestration21
- reregistrations18
- restrengthening24
- restrictionisms22
- restrictionists19
- restrictiveness23
- retransmissions20
- retroactivities22
- retrogradations19
- retrogressively24
- retroperitoneal20
- retroreflection23
- retroreflective26
- retroreflectors22
- retrospectively28
- sabermetricians25
- semiabstraction25
- semiterrestrial19
- semitranslucent25
- semitransparent23
- spectrographies28
- spectroscopists27
- stereochemistry25
- stoichiometries23
- straightforward26
- straightjackets35
- straitjacketing34
- straitlacedness21
- stratifications22
- stratovolcanoes24
- strenuousnesses19
- streptobacillus27
- streptothricins24
- strikebreakings29
- strongyloidoses22
- strongyloidosis22
- structuralizing33
- subcontraoctave30
- submetacentrics29
- supernutritions22
- superpatriotism25
- superstructural25
- superstructures24
- supersymmetries27
- symmetricalness28
- symmetrizations33
- technostructure26
- tetragrammatons24
- tetrahydrofuran25
- tetramethyllead25
- theatricalities21
- theatricalizing33
- thermochemistry30
- thunderstricken28
- thunderstriking27
- toastmistresses18
- tractablenesses23
- traditionalisms21
- traditionalists18
- traditionalized28
- traditionalizes27
- transaminations21
- transcendencies25
- transcriptional24
- transferability25
- transfiguration23
- transformations23
- transhistorical22
- transilluminate23
- transistorising19
- transistorizing28
- translatability23
- transliterating20
- transliteration18
- transmigrations22
- transmissometer22
- transmogrifying29
- transparentized30
- transparentizes29
- transparentness21
- transpirational21
- transplantation22
- transportations20
- transpositional21
- transsexualisms28
- transubstantial22
- transvaluations23
- traumatizations29
- treacherousness22
- tremulousnesses22
- triangularities20
- trichomonacidal29
- trichomonacides28
- trifluoperazine33
- trigonometrical25
- trihalomethanes24
- trinitrotoluene19
- trisoctahedrons22
- trivializations30
- troubleshooters22
- troubleshooting25
- troublesomeness24
- troublousnesses22
- trueheartedness20
- trustworthiness22
- trypanosomiases24
- trypanosomiasis24
- ultracentrifuge27
- ultracommercial30
- ultraconvenient27
- ultrademocratic27
- ultrafastidious22
- ultrafiltration22
- ultraliberalism25
- ultramarathoner23
- ultramicroscope29
- ultramicrotomes26
- ultramodernists22
- ultramontanisms25
- ultraprecisions24
- ultrasonography27
- ultrastructural23
- ultrastructures22
- ultravirilities22
- uncontroversial26
- undemonstrative26
- undernutritions21
- unextraordinary28
- unobtrusiveness26
- unreconstructed26
- unsymmetrically32
- untraditionally23
- vasoconstrictor26
- ventriloquially35
- ventriloquistic34
- ventriloquizing43