1. an officer next in rank to a president who serves as president in the president's absence.
2. an officer next in rank to a president who serves as a deputy to the president or oversees a special division or function.
3. (caps.) U.S. Govt.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. See table under president. Also,vice'-pres'ident.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.