5 letter words:
aback13,
banak11,
abuna7,
4 letter words:
back12,
buck12,
bank10,
bauk10,
bunk10,
cauk10,
knub10,
nabk10,
abac8,
banc8,
caba8,
kana8,
kuna8,
buna6,
3 letter words:
kab9,
aka7,
auk7,
bac7,
cab7,
cub7,
aba5,
baa5,
ban5,
bun5,
caa5,
can5,
nab5,
nub5,
ana3,
aua3,
2 letter words:
ka6,
ab4,
ba4,
aa2,
an2,
na2,
nu2,
un2,