Definition of "blackout"

blackout

/ˈblæk.aʊt/

noun
countable and uncountable, plural blackouts
1. A temporary loss of consciousness.
2. A temporary loss of memory.
3. A large-scale power failure, and resulting loss of electricity to consumers.
  Quotations
  The repairs at the Koeberg Power Station in the Western Cape were on schedule for completion in the third week of May. This follows huge blackouts related to the problems at the power supplier since November.
  2006 May 13, Weekend Argus, page 5
  There have been several examples of space weather affecting power grids in the last few decades, notably blackouts caused by GICs [geomagnetically induced currents] in Canada in 1989 and Sweden in 2003.
  2023 November 15, Prof. Jim Wild, “This train was delayed because of bad weather in space”, in RAIL, number 996, page 30
4. An instance of censorship, especially a temporary one.
5. (Internet) An intentional outage of a website or other online service, typically as a form of protest.
  Quotations
  A group of Redditors, many of whom are moderators, organized a temporary boycott, with participating subreddits going private or restricted for 48 hours starting on Monday. A Twitch stream tracking the blackout claimed that nearly 8,500 subreddits, some with tens of millions of subscribers, had gone dark by Tuesday afternoon.
  2023 June 14, Sara Morrison, “The ongoing Reddit Blackout, explained”, in Vox‎
6. (historical) 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.
  Quotations
  In co-operation with the Government departments, the British railway companies prepared their stations, offices, docks, hotels, trains, and other premises for the necessary blackout of lighting that it was realised would be required in a state of emergency, and in the case of the experimental voluntary blackouts which took place in July and August the railway companies concerned co-operated in every way possible.
  1939 November, Charles E. Lee, “Railways and the War — I”, in Railway Magazine, page 317
7. (attributive) The blocking out of as much light as possible.
8. (slang, criminology, rare) A mass murder committed, usually in an urban area, to eliminate potential witnesses of a previous crime.
verb
third-person singular simple present blackouts, present participle blackouting, simple past and past participle blackouted
1. (nonstandard) Alternative form of black out
  Quotations
  Scouts assisted Mabel Smythe Building officials in blackouting windows.
  1941, Annual Report of the Boy Scouts of America: Letter from the Chief Scout Executive Transmitting the Annual Report of the Boy Scouts of America ... as Required by Federal Charter, Boy Scouts of America, page 37
  As blades in night's chest buried, Voraciously my eyes strike, the silent Warsaw evening, my city blackouted throughout...
  2013, Dr Pauline Fairclough, Twentieth-Century Music and Politics: Essays in Memory of Neil Edmunds, Ashgate Publishing, Ltd.
  We had some inconvenience, such as food and petrol rationing, blackouting of homes and work places.
  2015, Helen Brown, Reflections: Australian Stories from My Father's Past
  'After recovering I 'blackouted' so much that I did not wake up until 10,000 ft below.' Zumbach's account, apart from the detailed description of his dogfight, also highlights the subject of the Polish pilots communicating in the air ...
  2018, Peter Sikora, The Polish 'Few': Polish Airmen in the Battle of Britain, Casemate Publishers
  Sarla started weeping and rushed to pull Jagan up. Jagan had banged his head into a wall and blackouted for a few moments. As his vision returned, he saw all his writings that he had lovingly been collecting […]
  2021, Jitendra Dixit, Bombay 3, Bloomsbury Publishing