definition of
MO

[1] #1 MO n. [moment, mo, minute, second, bit] an indefinitely short time; "wait just a moment"; "in a mo"; "it only takes a minute"; "in just a bit". wn

[2] #2 MO n. [molybdenum, Mo, atomic number 42] a polyvalent metallic element that resembles chromium and tungsten in its properties; used to strengthen and harden steel. wn

[3] #3 MO n. [Missouri, Show Me State] 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. wn