The blocking out of as much light as possible.
A large-scale power failure, and resulting loss of electricity to consumers.
A temporary loss of memory.
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.
A temporary loss of consciousness.
An instance of censorship, especially a temporary one.
Intelligence, cleverness.
The quality of being bright.
The perceived luminance of an object.