15 letters
- radiotelemetric23
- radiotelephones23
- radiotherapists21
- rapaciousnesses23
- rapturousnesses21
- rationalization27
- recalcitrancies26
- rechoreographed28
- rechromatograph30
- reconcentrating26
- reconcentration24
- reconfiguration26
- reconsecrations23
- reconsideration21
- redintegrations20
- refractometries24
- refrangibleness26
- reincorporating25
- reincorporation23
- reinvigorations23
- rememberability30
- remonstratively26
- reorchestrating23
- reorchestration21
- repairabilities22
- rephotographing30
- reregistrations18
- retransmissions20
- retrogradations19
- roentgenography28
- sacramentalisms26
- sacramentalists23
- semiabstraction25
- semipornography31
- semitranslucent25
- semitransparent23
- separablenesses23
- silviculturally30
- sinterabilities20
- socioculturally28
- solderabilities21
- spectrographies28
- sporangiophores26
- stadtholderates20
- stockbrokerages31
- straightforward26
- straightjackets35
- straitjacketing34
- straitlacedness21
- stratifications22
- stratovolcanoes24
- structuralizing33
- subcontraoctave30
- subterraneously24
- sulfinpyrazones36
- superablenesses24
- superabsorbents26
- superabundances29
- superabundantly29
- superactivities26
- superannuations23
- superbureaucrat27
- supernaturalism25
- supernaturalist22
- supernumeraries24
- superparasitism25
- supersaturating23
- supersaturation21
- superstructural25
- telegraphically30
- telephotography30
- temerariousness20
- temperamentally29
- temperatenesses22
- temporarinesses22
- teratocarcinoma25
- tetragrammatons24
- tetrahydrofuran25
- tetramethyllead25
- thalassocracies24
- therapeutically28
- topographically32
- 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
- trifluoperazine33
- turbogenerators22
- typographically34
- tyrannosauruses21
- ultracentrifuge27
- ultracommercial30
- ultraconvenient27
- ultrademocratic27
- ultrafastidious22
- ultrafiltration22
- ultraliberalism25
- ultramarathoner23
- ultramicroscope29
- ultramicrotomes26
- ultramodernists22
- ultramontanisms25
- ultraprecisions24
- ultrasonography27
- ultrastructural23
- ultrastructures22
- ultravirilities22
- unadulteratedly24
- unalterableness23
- unanswerability27
- unchoreographed30
- undemonstrative26
- underactivities25
- undesirableness23
- unendurableness25
- unextraordinary28
- unfavorableness29
- unnaturalnesses21
- untraditionally23
- upgradabilities26
- venerablenesses25
- veraciousnesses24
- voraciousnesses24
- vulnerabilities26
- warrantableness24
- withdrawnnesses26
- xerographically36
- xeroradiography32
- zoogeographical37