gag order

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

• noun A court order forbidding parties in a legal action, lawyers, witnesses, and jurors, from making statements to the press regarding an ongoing case in which they are participating.

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

• noun law An order issued by a court prohibiting specified persons from discussing a case outside limitations set by the court.
• noun informal Any directive from a person in authority prohibiting another person from speaking about a certain thing.

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

• noun a court order restricting information or comment by the participants involved in a lawsuit