7 letter words:
biotope11,
6 letter words:
bootie8,
5 letter words:
boite7,
topoi7,
4 letter words:
bite6,
boot6,
obit6,
oboe6,
poet6,
tope6,
topi6,
topo6,
3 letter words:
bop7,
bet5,
bio5,
bit5,
boo5,
bot5,
obe5,
obi5,
ope5,
opt5,
pet5,
pie5,
pit5,
poi5,
poo5,
pot5,
tip5,
top5,
oot3,
tie3,
toe3,
too3,
2 letter words:
be4,
bi4,
bo4,
op4,
pe4,
pi4,
et2,
it2,
oe2,
oi2,
ti2,
to2,