5 letter words:
fifer11,
brief10,
fiber10,
fibre10,
4 letter words:
biff12,
fief10,
fife10,
riff10,
fire7,
reif7,
rife7,
bier6,
brie6,
3 letter words:
eff9,
iff9,
fib8,
fer6,
fie6,
fir6,
ref6,
rif6,
reb5,
rib5,
ire3,
rei3,
2 letter words:
ef5,
fe5,
if5,
be4,
bi4,
er2,
re2,