5 letter words:
robot7,
turbo7,
4 letter words:
boor6,
boot6,
bort6,
bout6,
broo6,
brut6,
root4,
roto4,
rout4,
toro4,
tour4,
3 letter words:
boo5,
bot5,
bro5,
bur5,
but5,
orb5,
rob5,
rub5,
tub5,
urb5,
oot3,
ort3,
our3,
out3,
rot3,
rut3,
too3,
tor3,
2 letter words:
bo4,
or2,
to2,
ut2,