9 letter words:
petrifier14,
7 letter words:
prefire12,
ferrite10,
fierier10,
reifier10,
6 letter words:
prefer11,
feirie9,
ferret9,
refire9,
periti8,
perter8,
pitier8,
retire6,
5 letter words:
firer8,
freer8,
frere8,
frier8,
refer8,
refit8,
rifer8,
peter7,
prier7,
riper7,
tripe7,
retie5,
trier5,
4 letter words:
feet7,
fere7,
fete7,
fire7,
free7,
fret7,
frit7,
reef7,
reft7,
reif7,
rife7,
rift7,
tref7,
peer6,
pere6,
peri6,
pert6,
pier6,
pree6,
ripe6,
tipi6,
trip6,
rete4,
rite4,
tier4,
tire4,
tree4,
3 letter words:
eft6,
fee6,
fer6,
fet6,
fie6,
fir6,
fit6,
ref6,
rif6,
pee5,
per5,
pet5,
pie5,
pit5,
rep5,
rip5,
tip5,
ere3,
err3,
ire3,
ree3,
rei3,
ret3,
tee3,
tie3,
2 letter words:
ef5,
fe5,
if5,
pe4,
pi4,
er2,
et2,
it2,
re2,
ti2,