5 letter words:
freon8,
4 letter words:
fern7,
foen7,
fone7,
fore7,
froe7,
orfe7,
oner4,
rone4,
3 letter words:
erf6,
fen6,
fer6,
foe6,
fon6,
for6,
fro6,
nef6,
orf6,
ref6,
eon3,
ern3,
nor3,
one3,
ore3,
ren3,
reo3,
roe3,
2 letter words:
ef5,
fe5,
of5,
en2,
er2,
ne2,
no2,
oe2,
on2,
or2,
re2,