4 letters
- refs7
- regs6
- rein5
- reis4
- rems7
- rend6
- rent5
- repo7
- repp10
- reps7
- resh6
- rest4
- rets4
- revs8
- rhus7
- rins5
- ripe7
- rips7
- rise4
- roes4
- rope7
- rose4
- roue5
- roup8
- rube8
- rubs8
- rude6
- rued6
- ruer5
- rues5
- rugs7
- ruin6
- rule6
- rump11
- rums8
- rune6
- rung8
- runs6
- runt6
- ruse5
- rush7
- rusk9
- rust5
- ruts5
- ryes6
- sane5
- scup11
- sear4
- seen5
- seep7
- seer4
- send6
- sene5
- sent5
- sept7
- sera4
- sere4
- serf7
- sers4
- sewn8
- shun8
- sine5
- sipe7
- sire4
- skep11
- slue6
- slur6
- snap8
- sned6
- snip8
- snub9
- snug8
- snye7
- sone5
- sore4
- sorn5
- soup8
- sour5
- spae7
- span8
- spar7
- spec10
- sped8
- spew10
- spin8
- spry9
- spud9
- spue8
- spun9
- spur8
- step7
- stun6
- sued6
- suer5
- sues5
- suet5
- sump11
- sung8
- sunk10
- sunn7
- suns6
- supe8
- sups8
- sura5
- surd6
- sure5
- surf8
- syne7
- tens5
- tern5
- true5
- tune6
- tuns6
- tups8
- turn6
- ukes9
- umps11
- unbe9
- unde7
- upas8
- upon9
- urbs8
- urds6
- urea5
- urge7
- urns6
- ursa5
- urus6
- used6
- user5
- uses5
- wens8
- wren8
- yens7
- yups10