9 letter words:
fifteenth18,
7 letter words:
fifteen13,
6 letter words:
infeft12,
theine9,
nettie6,
tentie6,
5 letter words:
fifth14,
hefte11,
theft11,
thief11,
feint8,
fient8,
fitte8,
teeth8,
tenth8,
thein8,
thete8,
thine8,
tithe8,
ettin5,
tenet5,
4 letter words:
fief10,
fife10,
heft10,
niff10,
teff10,
tiff10,
ethe7,
feen7,
feet7,
feni7,
fent7,
fete7,
fett7,
fine7,
fitt7,
hent7,
hete7,
hint7,
neif7,
nief7,
nife7,
teth7,
thee7,
then7,
thin7,
tift7,
eine4,
eten4,
nete4,
nett4,
nite4,
teen4,
tene4,
tent4,
tete4,
tine4,
tint4,
tite4,
3 letter words:
eff9,
feh9,
iff9,
eft6,
eth6,
fee6,
fen6,
fet6,
fie6,
fin6,
fit6,
hen6,
het6,
hie6,
hin6,
hit6,
nef6,
nth6,
tef6,
the6,
een3,
ene3,
nee3,
net3,
nie3,
nit3,
tee3,
ten3,
tet3,
tie3,
tin3,
tit3,
2 letter words:
ef5,
eh5,
fe5,
he5,
hi5,
if5,
ee2,
en2,
et2,
in2,
it2,
ne2,
te2,
ti2,