5 letter words:
prune7,
4 letter words:
enuf7,
fern7,
pern6,
puer6,
pure6,
rune4,
3 letter words:
erf6,
fen6,
fer6,
feu6,
fun6,
fur6,
nef6,
ref6,
nep5,
pen5,
per5,
pre5,
pun5,
pur5,
rep5,
urp5,
ern3,
nur3,
ren3,
rue3,
run3,
ure3,
urn3,
2 letter words:
ef5,
fe5,
pe4,
up4,
en2,
er2,
ne2,
nu2,
re2,
un2,
ur2,