vetonoun/ˈviːtəʊ/

• 1

  A political right to disapprove of (and thereby stop) the process of a decision, a law etc.

• 2

  An invocation of that right.

  • I called Haig in and told him that I wanted to veto the agricultural appropriations bill we had discussed in the Cabinet meeting on Tuesday, because I did not want Ford to have to do it on his first day as President. Haig brought the veto statement in, and I signed it. It was the last piece of legislation I acted on as President.
  • The failure on Wednesday to overturn Mr. Cooper’s veto was among the most dramatic consequences of Democratic legislative victories in North Carolina last November, which broke Republican supermajorities in both chambers and made it easier for Mr. Cooper’s vetos to survive.
• 3

  An authoritative prohibition or negative; a forbidding; an interdiction.

  • This contemptuous veto of her husband's on any intimacy with her family.
• 4

  A technique or mechanism for discarding what would otherwise constitute a false positive in a scientific experiment.

  • An outer detector (OD) region will act as both a passive shield for low energy backgrounds and an active veto for cosmic ray muons.

vetoverb/ˈviːtəʊ/

• 1

  To use a veto against.

  • The president vetoed the bill.
  • The railway was in fact shifted in 1937 a little to the west, over a distance of a quarter-mile, to make room for the by-pass at this point, but complete abandonment was firmly vetoed because of the proved strategic value of the line.
• 2

  To countermand.

  • Mom and Dad vetoed our menu preferences for the holiday meal.