Definitions of Mo:
- noun: a polyvalent metallic element that resembles chromium and tungsten in its properties; used to strengthen and harden steel
- noun: a midwestern state in central United States; a border state during the American Civil War, Missouri was admitted to the Confederacy without actually seceding from the Union
- name: A surname (rare: 1 in 100000 families; popularity rank in the U.S.: #16063)