7 letter words:
fixatif20,
5 letter words:
affix18,
fixit15,
4 letter words:
faix14,
fixt14,
ixia11,
taxi11,
fifi10,
tiff10,
fiat7,
3 letter words:
fax13,
fix13,
tax10,
tix10,
aff9,
iff9,
aft6,
fat6,
fit6,
ait3,
ita3,
tai3,
2 letter words:
ax9,
xi9,
fa5,
if5,
ai2,
at2,
it2,
ta2,
ti2,