7 letter words:
biffins15,
6 letter words:
biffin14,
5 letter words:
biffs13,
niffs11,
sniff11,
finis8,
4 letter words:
biff12,
fifi10,
niff10,
fibs9,
fini7,
fins7,
bins6,
ibis6,
nibs6,
snib6,
nisi4,
3 letter words:
iff9,
fib8,
fin6,
ifs6,
sif6,
bin5,
bis5,
nib5,
sib5,
ins3,
nis3,
sin3,
2 letter words:
if5,
bi4,
in2,
is2,
si2,