6 letter words:
tiffin12,
5 letter words:
unfit8,
4 letter words:
fifi10,
niff10,
nuff10,
tiff10,
tuff10,
fini7,
inti4,
unit4,
3 letter words:
iff9,
fin6,
fit6,
fun6,
nit3,
nut3,
tin3,
tui3,
tun3,
uni3,
2 letter words:
if5,
in2,
it2,
nu2,
ti2,
un2,
ut2,