The term veto is used in reference to the president rejecting legislation and sending it back to the legislative body as opposed to approving and signing it into law.
U.S. Senate Definition
The procedure established under the Constitution by which the president refuses to approve a bill or joint resolution and thus prevents its enactment into law. A regular veto occurs when the president returns the legislation to the house in which it originated. The president usually returns a vetoed bill with a message indicating his reasons for rejecting the measure. The veto can be overridden only by a two-thirds vote in both the Senate and the House. Summary of Bills Vetoed, 1789-present