7 letter words:
fatback18,
5 letter words:
aback13,
abaft10,
4 letter words:
fuck13,
back12,
buck12,
tack10,
tuck10,
fact9,
kata8,
taka8,
tufa7,
abut6,
acta6,
tabu6,
tuba6,
3 letter words:
kaf10,
kab9,
fab8,
fub8,
auk7,
cab7,
cub7,
kat7,
aft6,
fat6,
aba5,
act5,
baa5,
bat5,
but5,
cat5,
cut5,
tab5,
tub5,
tau3,
uta3,
2 letter words:
ka6,
fa5,
ab4,
ba4,
aa2,
at2,
ta2,
ut2,