- monoamine oxidase, MAO - an enzyme that catalyzes the oxidation of many body compounds (e.g., epinephrine and norepinephrine and serotonin)
--1 is a kind of enzyme
- Mao, Mao Zedong, Mao Tsetung - Chinese communist leader (1893-1976)
--2 is a kind of communist, commie; revolutionist, revolutionary, subversive, subverter