5 letter words:
furor8,
burro7,
4 letter words:
forb9,
four7,
biro6,
birr6,
brio6,
burr6,
3 letter words:
fib8,
fob8,
fub8,
fir6,
for6,
fou6,
fro6,
fur6,
rif6,
bio5,
bro5,
brr5,
bur5,
obi5,
orb5,
rib5,
rob5,
rub5,
urb5,
our3,
2 letter words:
if5,
of5,
bi4,
bo4,
oi2,
or2,