13 letter words:
preterperfect22,
9 letter words:
perfecter16,
8 letter words:
preerect12,
reperepe12,
ferreter11,
fetterer11,
7 letter words:
perfect14,
prefect14,
percept13,
precept13,
creeper11,
fretter10,
referee10,
erecter9,
reerect9,
6 letter words:
perfet11,
prefer11,
refect11,
peeper10,
recept10,
ferret9,
fetter9,
reefer9,
perter8,
petter8,
teepee8,
tercet8,
retree6,
teeter6,
terete6,
terret6,
5 letter words:
creep9,
crepe9,
crept9,
peece9,
peepe9,
perce9,
ferer8,
freer8,
freet8,
frere8,
refer8,
terfe8,
erect7,
peter7,
petre7,
tepee7,
terce7,
4 letter words:
cepe8,
peep8,
perp8,
prep8,
repp8,
feer7,
feet7,
fere7,
fete7,
fett7,
free7,
fret7,
reef7,
reft7,
terf7,
tref7,
cere6,
cert6,
cete6,
cree6,
epee6,
peer6,
pere6,
pert6,
pree6,
rete4,
teer4,
tete4,
tree4,
tret4,
3 letter words:
cep7,
pec7,
pep7,
eft6,
erf6,
fee6,
fer6,
fet6,
ref6,
tef6,
cee5,
pee5,
per5,
pet5,
pre5,
rec5,
rep5,
tec5,
ere3,
err3,
ree3,
ret3,
tee3,
tet3,
2 letter words:
ef5,
fe5,
pe4,
ee2,
er2,
et2,
re2,
te2,