7 letter words:
unruffe13,
5 letter words:
ruffe11,
4 letter words:
nuff10,
ruff10,
enuf7,
fern7,
rune4,
3 letter words:
eff9,
erf6,
fen6,
fer6,
feu6,
fun6,
fur6,
nef6,
ref6,
ern3,
nur3,
ren3,
rue3,
run3,
ure3,
urn3,
2 letter words:
ef5,
fe5,
en2,
er2,
ne2,
nu2,
re2,
un2,
ur2,