6 letter words:
unopen8,
5 letter words:
unpen7,
4 letter words:
pepo8,
poop8,
pope8,
nope6,
open6,
peon6,
pone6,
poon6,
upon6,
neon4,
none4,
noon4,
noun4,
3 letter words:
pep7,
pop7,
pup7,
ope5,
pen5,
poo5,
pun5,
upo5,
eon3,
noo3,
nun3,
one3,
ono3,
2 letter words:
op4,
pe4,
up4,
en2,
ne2,
no2,
nu2,
oe2,
on2,
un2,