6 letter words:
prefix18,
5 letter words:
fixer15,
refix15,
4 letter words:
prex13,
fire7,
reif7,
rife7,
peri6,
pier6,
ripe6,
3 letter words:
fix13,
pix12,
rex10,
fer6,
fie6,
fir6,
ref6,
rif6,
per5,
pie5,
rep5,
rip5,
ire3,
rei3,
2 letter words:
ex9,
xi9,
ef5,
fe5,
if5,
pe4,
pi4,
er2,
re2,