7 letter words:
refuter10,
6 letter words:
ferret9,
refute9,
ureter6,
5 letter words:
freer8,
frere8,
refer8,
truer5,
4 letter words:
feet7,
fere7,
fete7,
free7,
fret7,
reef7,
reft7,
tref7,
turf7,
rete4,
ruer4,
tree4,
true4,
3 letter words:
eft6,
fee6,
fer6,
fet6,
feu6,
fur6,
ref6,
ere3,
err3,
ree3,
ret3,
rue3,
rut3,
tee3,
ute3,
2 letter words:
ef5,
fe5,
er2,
et2,
re2,
ut2,