(UK) A defence advisory notice, an official (but unenforceable) request to news editors not to publish or broadcast items on specified subjects for reasons of national security.

(law) Notice of a fact which is created by operation of law, despite a lack of actual notice.

(espionage) An announcement of dismissal of an agent or source an intelligence agency considers to have become unreliable.

(law) In the law of evidence, the power of a court to deem the burden of proof to be established as to a particular fact without the introduction of evidence, because the fact is one that is a matter of common knowledge, or is readily demonstrated by reference to sources of unquestionable authority.

(law) A warning endorsed on a court order, notifying the recipient that he or she is liable to committal to prison for breach of the order.

(idiomatic, transitive) To ignore.

(intransitive, often with of) To notice; to take note.

A board, hanging on a wall, on which notices and announcements are posted. / (Internet) An online forum where users can post and read messages.

(idiomatic) Immediately; instantaneously; without need of warning.

Used other than figuratively or idiomatically: see give, notice. / (idiomatic) To announce one's intent to leave a job; to inform an employer that one is leaving.