8 letter words:
spiffies16,
6 letter words:
spiffs14,
5 letter words:
spiff13,
fiefs11,
fifes11,
spifs10,
seifs8,
pises7,
sipes7,
spies7,
issei5,
4 letter words:
effs10,
fief10,
fife10,
fifi10,
spif9,
feis7,
fess7,
seif7,
pies6,
pise6,
piss6,
psis6,
seps6,
sipe6,
sips6,
spie6,
seis4,
sies4,
3 letter words:
eff9,
iff9,
efs6,
fes6,
fie6,
ifs6,
sif6,
pes5,
pie5,
pis5,
psi5,
sip5,
ess3,
sei3,
sis3,
2 letter words:
ef5,
fe5,
if5,
pe4,
pi4,
es2,
is2,
si2,
