mo
noun
1
a moment UK, 1896.
2
in a prison, a prisoner subject to mental observation US, 2000.
3
a moustache AUSTRALIA, 1894.
4
a month US, 1928.
5
a homosexual US, 1968
MO
noun
1
a criminal's method of operating. From the Latin modus operandi US, 1954.
2
marijuana. Also without the capitals US, 1977