c.1375, "appointed governor of a province, chosen leader of a body of persons," from L. præsidentum (nom. præsidens) "president, governor," noun use of prp. of præsidere "to act as head or chief" (see preside). First use for "chief executive officer of a republic" is in U.S. Constitution (1787), from earlier use for "officer in charge of the Continental Congress" (1774); it had been used of chief officers of banks from 1781, of individual colonies since 1608 (originally Virginia) and heads of colleges since 1464. Slang shortening prez is recorded from 1892.