5 letter words:
rumba9,
umbra9,
4 letter words:
abba8,
baba8,
babu8,
barb8,
barm8,
burb8,
arum6,
bura6,
maar6,
mara6,
mura6,
aura4,
3 letter words:
bam7,
bub7,
bum7,
aba5,
ama5,
amu5,
arb5,
arm5,
baa5,
bar5,
bra5,
bur5,
mar5,
ram5,
rub5,
rum5,
urb5,
2 letter words:
ab4,
am4,
ba4,
ma4,
mu4,
um4,
aa2,
ar2,