7 letter words:
fibroin12,
6 letter words:
fibrin11,
fiorin9,
5 letter words:
fibro10,
inorb7,
oribi7,
robin7,
4 letter words:
forb9,
frib9,
fini7,
fino7,
firn7,
foin7,
info7,
biro6,
born6,
brin6,
brio6,
inro4,
iron4,
noir4,
nori4,
roin4,
3 letter words:
fib8,
fob8,
fin6,
fir6,
fon6,
for6,
fro6,
orf6,
rif6,
bin5,
bio5,
boi5,
bon5,
bor5,
bro5,
nib5,
nob5,
obi5,
orb5,
rib5,
rob5,
ion3,
nor3,
rin3,
2 letter words:
if5,
of5,
bi4,
bo4,
ob4,
in2,
io2,
no2,
oi2,
on2,
or2,