6 letter words:
burger9,
bruter8,
5 letter words:
gebur8,
brute7,
buret7,
rebut7,
tuber7,
regur6,
urger6,
truer5,
4 letter words:
berg7,
burg7,
grub7,
brer6,
brut6,
burr6,
bute6,
rube6,
tube6,
gert5,
grue5,
guru5,
tegu5,
trug5,
urge5,
ruer4,
ruru4,
true4,
3 letter words:
beg6,
bug6,
gub6,
bet5,
brr5,
bru5,
bur5,
but5,
reb5,
rub5,
tub5,
urb5,
erg4,
get4,
gue4,
gur4,
gut4,
reg4,
rug4,
teg4,
tug4,
err3,
ret3,
rue3,
rut3,
ure3,
ute3,
utu3,
2 letter words:
be4,
gu3,
ug3,
er2,
et2,
re2,
te2,
ur2,
ut2,