4 letters
- ouch10
- pech12
- puce11
- pure8
- purr8
- race7
- rare4
- rear4
- rebs7
- reck11
- recs7
- rein5
- rend6
- rent5
- resh6
- rhea6
- rhus7
- rice7
- rich9
- robe7
- roue5
- rube8
- rubs8
- ruby10
- ruck12
- rude6
- rued6
- ruer5
- rues5
- ruin6
- rule6
- rune6
- rung8
- runs6
- runt6
- ruse5
- rush7
- ruth7
- shun8
- snub9
- such10
- suer5
- sure5
- tern5
- then7
- thru7
- true5
- tube8
- tune6
- turn6
- unbe9
- unci9
- unco9
- unde7
- urbs8
- urea5
- urge7
- uric8
- urns6
- user5
- verb11
- when10
- wren8
- yech11
- yuch12
- zebu17