13 letters
- spontaneously22
- sporopollenin23
- sportfishings24
- sportscasters19
- sportscasting22
- sportsmanlike25
- sportsmanship25
- sportswriters19
- sportswriting22
- sprachgefuhls30
- spreadability23
- sprightliness22
- springinesses20
- stratospheres18
- stratospheric21
- subspecialist24
- subspecialize33
- superspecials24
- suspensefully26
- tablespoonful26
- teleutospores18
- thermospheres23
- thermospheric26
- transparences21
- transparently21
- transpersonal19
- transpiercing23
- transpiration18
- transplanters19
- transplanting22
- transportable21
- transposition18
- triphosphates23
- unrespectable25
- unspecialized32
- unspecifiable28
- unspectacular26
- urediniospore19
- waspishnesses22
- zoosporangium32