What is the meaning of Blackout?

A temporary loss of consciousness.

A temporary loss of memory.

A large-scale power failure, and resulting loss of electricity to consumers.

An instance of censorship, especially a temporary one.

An intentional outage of a website or other online service, typically as a form of protest.

The mandatory blocking of all light emanating from buildings, as well as outdoor and street lighting as a measure against aerial bombing or naval attack, as imposed during, e.g., World War II.

The blocking out of as much light as possible.

A mass murder committed, usually in an urban area, to eliminate potential witnesses of a previous crime.

Alternative form of black out

Alternative form of blecaute

blackout (clarification of this definition is needed)

Source: wiktionary.org