MO

Derived from English Macao.

MO

1. (international standards) ISO 3166-1 alpha-2 country code for Macau.

   Synonym: MAC (alpha-3)

MO

1. Abbreviation of Missouri: a state of the United States.
2. (stock ticker symbol) Abbreviation of Philip Morris Companies, now Altria Group.
3. (Judaism) Initialism of Modern Orthodox.

MO (countable and uncountable, plural MOs)

1. Initialism of modus operandi.

   Alternative forms: m.o., M.O.

   • 1981, James Ellroy, Brown's Requiem, page 207:

     The Big Man is everywhere. He knows my M.O.!!!!

   • 2022, Ling Ma, “Oranges”, in Bliss Montage, New York: Farrar, Straus and Giroux, →ISBN:

     This was her apartment, I gathered, and he was living here. That was his MO. He would leech onto some girl and eventually move into her home.

2. (banking) Initialism of money order.
3. (military, UK) Initialism of medical officer.
4. (chemistry) Initialism of molecular orbital.

MO (not comparable)

1. (dentistry) Initialism of mesio-occlusal.
2. (computing) Initialism of magnetooptical.

• “m.o. n.”, in Green’s Dictionary of Slang, Jonathon Green, 2016–present

• O&M, O.M., OM, om