4 letters
- ruer5
- rues5
- rugs7
- rule6
- rump11
- rums8
- rune6
- runs6
- ruse5
- rush7
- rusk9
- rust5
- ruts5
- ryes6
- same7
- scam10
- scar7
- scry9
- scud9
- scum11
- scup11
- scut8
- seam7
- sear4
- secs7
- sect7
- seem7
- seer4
- seme7
- semi7
- sera4
- sere4
- serf7
- sers4
- sice7
- sire4
- slue6
- slum9
- slur6
- smew10
- smug10
- smut8
- some7
- sore4
- sour5
- spec10
- spue8
- spur8
- stem7
- stum8
- such10
- suck12
- sued6
- suer5
- sues5
- suet5
- sumo8
- sump11
- sums8
- supe8
- sura5
- surd6
- sure5
- surf8
- swum11
- syce9
- term7
- true5
- ukes9
- umps11
- urbs8
- urds6
- urea5
- urge7
- uric8
- urns6
- ursa5
- urus6
- used6
- user5
- uses5