an officer next in rank to a president who serves as president in the president's absence.
an officer next in rank to a president who serves as a deputy to the president or oversees a special division or function.
(initial capital letters) U.S. Government. the officer of this rank who is elected at the same time as the president and who succeeds to the presidency on the resignation, removal, death, or disability of the president.
British Dictionary definitions for vice presidency
an officer ranking immediately below a president and serving as his deputy. A vice president takes the president's place during his absence or incapacity, after his death, and in certain other circumstances Abbreviation VP, V. Pres