6 letter words:
burger9,
future9,
5 letter words:
fugue9,
brute7,
buret7,
rebut7,
tuber7,
urger6,
truer5,
4 letter words:
frug8,
fugu8,
berg7,
burg7,
fret7,
grub7,
reft7,
tref7,
turf7,
brut6,
burr6,
bute6,
rube6,
tube6,
grue5,
guru5,
trug5,
urge5,
ruer4,
true4,
3 letter words:
fub8,
fug7,
beg6,
bug6,
eft6,
fer6,
fet6,
feu6,
fur6,
ref6,
bet5,
brr5,
bur5,
but5,
reb5,
rub5,
tub5,
urb5,
erg4,
get4,
gut4,
reg4,
rug4,
teg4,
tug4,
err3,
ret3,
rue3,
rut3,
ute3,
2 letter words:
ef5,
fe5,
be4,
er2,
et2,
re2,
ut2,