6 letter words:
number10,
regnum9,
5 letter words:
begum10,
brume9,
umber9,
begun8,
brung8,
grume8,
rumen7,
4 letter words:
berm8,
numb8,
berg7,
bung7,
burg7,
germ7,
geum7,
grub7,
grum7,
bren6,
burn6,
menu6,
mure6,
neum6,
rube6,
unbe6,
genu5,
grue5,
guru5,
rung5,
urge5,
rune4,
3 letter words:
bum7,
beg6,
bug6,
gem6,
gum6,
meg6,
mug6,
ben5,
bun5,
bur5,
emu5,
men5,
mun5,
neb5,
nub5,
reb5,
rem5,
rub5,
rum5,
urb5,
eng4,
erg4,
gen4,
gnu4,
gun4,
neg4,
reg4,
rug4,
ern3,
rue3,
run3,
urn3,
2 letter words:
be4,
em4,
me4,
mu4,
um4,
en2,
er2,
ne2,
nu2,
re2,
un2,