4 letters
- once8
- ones5
- onto5
- onus6
- oots4
- open8
- opes7
- opts7
- opus8
- orad5
- oral5
- orbs7
- orca7
- orcs7
- ores4
- orle5
- orra4
- orts4
- osar4
- oses4
- ossa4
- ouds6
- ours5
- oust5
- outs5
- oval9
- oven9
- over8
- ovum12
- owes7
- owns8
- owse7
- oxen12
- oxes11
- oyer6
- oyes6
- pams10
- pane8
- pans8
- pant8
- pare7
- pars7
- part7
- pase7
- past7
- pate7
- pats7
- pave11
- pean8
- pear7
- peas7
- peat7
- peen8
- peer7
- pees7
- pens8
- pent8
- peon8
- perm10
- pert7
- peso7
- pest7
- pets7
- poem10
- poet7
- pome10
- poms10
- pone8
- pons8
- pore7
- porn8
- port7
- pose7
- post7
- pots7
- pour8
- pout8
- pram10
- prao7
- prat7
- prau8
- pree7
- proa7
- prom10
- pros7
- puma11
- puna9
- puns9
- punt9
- pure8
- purs8
- puts8
- qats13
- race7
- rads5
- raft7
- rage6
- rags6
- rain5
- rake8
- rale5
- rami7
- ramp10
- rams7
- rand6
- rang7
- rani5
- rank9
- rant5
- rape7
- raps7
- rapt7
- rare4
- rase4
- rash6
- rasp7
- rate4
- rath6
- rato4
- rats4
- rave8
- raws7
- rays6
- raze13
- read5
- real5
- ream7
- reap7
- rear4
- rebs7
- recs7
- rede5
- redo5
- reds5
- reed5
- reef7
- reek8
- reel5
- rees4
- refs7
- reft7
- regs6
- rein5
- reis4
- rems7
- rend6
- rent5
- repo7
- reps7
- resh6
- rest4
- rete4
- rets4
- revs8
- rhea6
- rhos6
- rhus7
- rias4
- rime7
- rims7
- rins5
- riot4
- rise4
- rite4
- rive8
- road5
- roam7
- roan5
- roar4
- robe7
- robs7
- rocs7
- rode5
- rods5
- roes4
- role5
- romp10
- roms7
- room7
- root4
- rope7
- rose4
- rosy6
- rota4
- rote4
- roti4
- rotl5
- roto4
- rots4
- roue5
- roup8
- rout5
- roux12
- rove8
- rows7
- rube8
- rubs8
- rude6
- rued6
- ruer5