6 letter words:
ferine9,
refine9,
5 letter words:
brief10,
fiber10,
fibre10,
finer8,
infer8,
biner7,
brine7,
4 letter words:
beef9,
feeb9,
fere7,
fern7,
fine7,
fire7,
firn7,
free7,
neif7,
reef7,
reif7,
rife7,
been6,
beer6,
bene6,
bier6,
bine6,
bree6,
bren6,
brie6,
brin6,
erne4,
rein4,
3 letter words:
fib8,
fee6,
fen6,
fer6,
fie6,
fin6,
fir6,
ref6,
rif6,
bee5,
ben5,
bin5,
neb5,
nib5,
reb5,
rib5,
ere3,
ern3,
ire3,
nee3,
ree3,
rei3,
rin3,
2 letter words:
ef5,
fe5,
if5,
be4,
bi4,
en2,
er2,
in2,
ne2,
re2,