6 letter words:
finner9,
5 letter words:
finer8,
infer8,
inner5,
renin5,
4 letter words:
feni7,
fern7,
fier7,
fine7,
fire7,
firn7,
neif7,
nief7,
nife7,
reif7,
rife7,
nine4,
rein4,
rine4,
3 letter words:
erf6,
fen6,
fer6,
fie6,
fin6,
fir6,
nef6,
ref6,
rif6,
ern3,
inn3,
ire3,
nie3,
rei3,
ren3,
rin3,
2 letter words:
ef5,
fe5,
if5,
en2,
er2,
in2,
ne2,
re2,