9 letter words:
bilirubin13,
8 letter words:
urobilin10,
6 letter words:
ribbon10,
robbin10,
biniou8,
5 letter words:
bilbo9,
blurb9,
blini7,
bourn7,
broil7,
bruin7,
burin7,
inorb7,
libri7,
oribi7,
robin7,
rubin7,
4 letter words:
blob8,
blub8,
bubo8,
bulb8,
burb8,
birl6,
biro6,
blin6,
blur6,
boil6,
born6,
boun6,
brin6,
brio6,
burl6,
burn6,
lobi6,
inro4,
iron4,
lino4,
lion4,
liri4,
loin4,
loir4,
lorn4,
loun4,
lour4,
nirl4,
noil4,
noir4,
nori4,
noul4,
nurl4,
ourn4,
roil4,
roin4,
roul4,
ruin4,
3 letter words:
bib7,
bob7,
bub7,
bin5,
bio5,
boi5,
bon5,
bor5,
bro5,
bru5,
bun5,
bur5,
lib5,
lob5,
nib5,
nob5,
nub5,
obi5,
orb5,
rib5,
rob5,
rub5,
urb5,
ion3,
lin3,
lor3,
lou3,
lur3,
nil3,
nor3,
nur3,
oil3,
our3,
rin3,
run3,
uni3,
urn3,
2 letter words:
bi4,
bo4,
ob4,
in2,
io2,
li2,
lo2,
no2,
nu2,
oi2,
on2,
or2,
ou2,
un2,
ur2,