5 letter words:
brigs8,
burgs8,
grubs8,
4 letter words:
zigs14,
bigs7,
brig7,
bugs7,
burg7,
gibs7,
grub7,
bris6,
burs6,
ribs6,
rubs6,
urbs6,
rigs5,
rugs5,
3 letter words:
biz14,
zig13,
big6,
bug6,
gib6,
bis5,
bur5,
bus5,
rib5,
rub5,
sib5,
sub5,
urb5,
rig4,
rug4,
sir3,
sri3,
2 letter words:
bi4,
is2,
si2,
us2,