To disallow.
To reject an option from a list of possibilities.
To make something impossible.
To cross an item out by drawing a straight line through it, as with a ruler.
To make unavailable.
To penalize (a state etc.) with sanctions.
To ratify; to make valid.
To give official authorization or approval to; to countenance.
An approval, by an authority, generally one that makes something valid.
A penalty, punishment, or some coercive measure, intended to ensure compliance; especially one adopted by several nations, or by an international body.
A law, treaty, or contract, or a clause within a law, treaty, or contract, specifying any of the above.