6 letter words:
burner8,
runner6,
5 letter words:
benne7,
enure5,
rerun5,
4 letter words:
been6,
beer6,
bene6,
bree6,
bren6,
bunn6,
burn6,
burr6,
rube6,
unbe6,
erne4,
nene4,
ruer4,
rune4,
3 letter words:
bee5,
ben5,
brr5,
bun5,
bur5,
neb5,
nub5,
reb5,
rub5,
urb5,
ere3,
ern3,
err3,
nee3,
nun3,
ree3,
rue3,
run3,
urn3,
2 letter words:
be4,
en2,
er2,
ne2,
nu2,
re2,
un2,