sanction

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun Authoritative permission or approval that makes a course of action valid. synonym: permission.
• noun Support or encouragement, as from public opinion or established custom.
• noun A consideration, influence, or principle that dictates an ethical choice.
• noun The penalty for noncompliance with a law or legal order.
• noun A penalty, specified or in the form of moral pressure, that acts to ensure compliance with a social standard or norm.
• noun A coercive measure adopted usually by several nations acting together against a nation violating international law.
• transitive verb To give official authorization or approval to.
• transitive verb To encourage or tolerate by indicating approval.
• transitive verb To penalize, as for violating a moral principle or international law.

from The Century Dictionary.

• To give authoritative permission or approval to: ratify; confirm; invest with validity or authority.
• To give countenance or support to; approve.
• Synonyms Allow, Permit, etc. See allow.
• noun The act of making sacred; the act of rendering authoritative as law; the act of decreeing or ratifying; the act of making binding, as by an oath.
• noun A decree; an ordinance; a law: as, the pragmatic sanction.
• noun The conferring of authority upon an opinion, practice, or sentiment; confirmation or support derived from public approval, from exalted testimony, or from the countenance of a person or body commanding respect.
• noun A provision of a law which enforces obedience by the enactment of rewards or penalties, called respectively remuneratory and punitive sanctions; hence, in utilitarian ethics, the knowledge of the pleasurable or painful consequences of an act, as making it moral or immoral.
• noun Synonyms and Authorization, countenance, support, warrant.

from the GNU version of the Collaborative International Dictionary of English.

• noun Solemn or ceremonious ratification; an official act of a superior by which he ratifies and gives validity to the act of some other person or body; establishment or furtherance of anything by giving authority to it; confirmation; approbation.
• noun Anything done or said to enforce the will, law, or authority of another.
• transitive verb To give sanction to; to ratify; to confirm; to approve.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun An approval, by an authority, generally one that makes something valid.
• noun A penalty, or some coercive measure, intended to ensure compliance; especially one adopted by several nations, or by an international body.
• noun A law, treaty, or contract, or a clause within a law, treaty, or contract, specifying the above.
• verb transitive To ratify; to make valid.
• verb transitive To give official authorization or approval to; to countenance.
• verb transitive To penalize (a State etc.) with sanctions.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• verb give religious sanction to, such as through on oath
• noun a mechanism of social control for enforcing a society's standards
• noun the act of final authorization
• verb give authority or permission to
• noun official permission or approval
• noun formal and explicit approval
• verb give sanction to