7 letter words:
briefer12,
furrier10,
burrier9,
6 letter words:
refire9,
burier8,
burrer8,
rubier8,
5 letter words:
brief10,
fiber10,
fibre10,
firer8,
freer8,
frere8,
frier8,
refer8,
rifer8,
brier7,
4 letter words:
beef9,
feeb9,
fere7,
fire7,
free7,
reef7,
reif7,
rife7,
beer6,
bier6,
birr6,
bree6,
brie6,
brrr6,
burr6,
rube6,
ruer4,
3 letter words:
fib8,
fub8,
fee6,
fer6,
feu6,
fie6,
fir6,
fur6,
ref6,
rif6,
bee5,
brr5,
bur5,
reb5,
rib5,
rub5,
urb5,
ere3,
err3,
ire3,
ree3,
rei3,
rue3,
2 letter words:
ef5,
fe5,
if5,
be4,
bi4,
er2,
re2,