4 letters
- rose4
- roue5
- rube8
- rubs8
- ruby10
- rude6
- rued6
- ruer5
- rues5
- ruff11
- rugs7
- rule6
- rums8
- rune6
- runs6
- ruse5
- rush7
- rusk9
- rust5
- ruts5
- ryes6
- sabe7
- safe7
- sear4
- seer4
- seif7
- self8
- sera4
- sere4
- serf7
- sers4
- sire4
- slub9
- slue6
- slur6
- snub9
- sorb7
- sore4
- sour5
- spue8
- spur8
- stub8
- suba8
- subs8
- sued6
- suer5
- sues5
- suet5
- supe8
- sura5
- surd6
- sure5
- surf8
- teff10
- tref7
- true5
- tube8
- tubs8
- tuff11
- turf8
- ukes9
- unbe9
- urbs8
- urds6
- urea5
- urge7
- urns6
- ursa5
- urus6
- used6
- user5
- uses5
- verb11
- webs10
- zebu17