1. veto, blackball, negative -- (vote against; refuse to endorse; refuse to assent; "The President vetoed the bill")
2. forbid, prohibit, interdict, proscribe, veto, disallow, nix -- (command against; "I forbid you to call me late at night"; "Mother vetoed the trip to the chocolate store"; "Dad nixed our plans")
veto can be used as a noun
1. veto -- (a vote that blocks a decision)
2. veto -- (the power or right to prohibit or reject a proposed or intended act (especially the power of a chief executive to reject a bill passed by the legislature))
1.
Linton has a prejudice against me we quarrelled at one time of our lives, with unchristian ferocity and, if you mention coming here to him, he'll put a veto on your visits altogether. - from Wuthering Heights by Emily Bronte