4 letters
- shin7
- shul8
- shun8
- shut7
- sick11
- sinh7
- sink9
- skag10
- skas8
- skat8
- skin9
- skua9
- slab8
- slub9
- snag7
- snap8
- snaw8
- snib8
- snob8
- snub9
- snug8
- soak8
- sock11
- souk9
- span8
- spun9
- stab7
- stub8
- stun6
- suba8
- subs8
- such10
- suck12
- sugh9
- sulk10
- sung8
- sunk10
- sunn7
- suns6
- sura5
- swab10
- swan8
- sync10
- tabs7
- tabu8
- tach9
- tack11
- tank9
- tans5
- task8
- taus5
- than7
- thus7
- tuba8
- tubs8
- tuck12
- tuna6
- tuns6
- tush7
- tusk9
- ughs9
- ukes9
- ulan7
- ulna7
- unai6
- unau7
- unbe9
- unci9
- unco9
- upas8
- urbs8
- urns6
- ursa5
- utas5
- vacs11
- vans9
- vaus9
- wabs10
- wack14
- wans8
- wash9
- wauk12
- yack13
- yaks10
- yank11
- yuan8
- yuca10
- yuch12
- yuck14
- yuks11