5 letter words:
brook11,
iroko9,
orbit7,
robot7,
4 letter words:
birk10,
book10,
bork10,
kobo10,
koto8,
rook8,
took8,
biro6,
boor6,
boot6,
bort6,
brio6,
brit6,
broo6,
obit6,
riot4,
root4,
roti4,
roto4,
tiro4,
tori4,
toro4,
trio4,
3 letter words:
kob9,
irk7,
kir7,
kit7,
koi7,
kor7,
bio5,
bit5,
boo5,
bot5,
bro5,
obi5,
orb5,
rib5,
rob5,
oot3,
ort3,
rot3,
too3,
tor3,
2 letter words:
ki6,
bi4,
bo4,
it2,
oi2,
or2,
ti2,
to2,