6 letter words:
bunger9,
burger9,
burner8,
5 letter words:
begun8,
brung8,
gebur8,
regur6,
urger6,
rerun5,
4 letter words:
berg7,
bung7,
burg7,
grub7,
bren6,
brer6,
burn6,
burr6,
rube6,
unbe6,
genu5,
gren5,
grue5,
gurn5,
guru5,
rung5,
urge5,
nurr4,
ruer4,
rune4,
ruru4,
3 letter words:
beg6,
bug6,
gub6,
ben5,
brr5,
bru5,
bun5,
bur5,
neb5,
nub5,
reb5,
rub5,
urb5,
eng4,
erg4,
gen4,
gnu4,
gue4,
gun4,
gur4,
neg4,
reg4,
rug4,
ern3,
err3,
nur3,
ren3,
rue3,
run3,
ure3,
urn3,
2 letter words:
be4,
gu3,
ug3,
en2,
er2,
ne2,
nu2,
re2,
un2,
ur2,