Definition of president:
an executive officer of a firm or corporation
the person who holds the office of head of state of the United States government; "the President likes to jog every morning"
the chief executive of a republic
the officer who presides at the meetings of an organization; "address your remarks to the chairperson"
the head administrative officer of a college or university
the office of the United States head of state; "a President is elected every four years"