English Reference
noun

blackout

n.
US /ˈbɫæˌkaʊt/ UK /blˈækaʊt/ black·out UK spelling blackout's, blackout's

  1. 01 B2 Upper Intermediate

    a period of time when there is no electricity in a building or area.

    a large-scale failure of electrical power supply to a specific geographic area.

    Simple

    The storm caused a massive blackout that left the whole city in the dark.

    In context

    The aging infrastructure was unable to handle the peak demand, resulting in a rolling blackout that affected several industrial districts.

    power cutoutage
  2. 02 B2 Upper Intermediate Medicine

    a short period when you are unconscious or cannot remember what happened.

    a temporary loss of consciousness or memory, often induced by medical conditions or substance use.

    Simple

    He had a total blackout and couldn't remember how he got home.

    In context

    The patient reported experiencing a brief blackout during the flight, prompting the medical team to investigate potential neurological causes.

    faintswoonmemory loss
  3. 03 C1 Advanced Formal

    when the government or an organization stops news or information from being shared.

    the official suppression or withholding of information, particularly by a government during a crisis.

    Simple

    The government imposed a media blackout during the military operation.

    In context

    Despite the official news blackout, reports of the protest began to leak out through encrypted messaging apps.

  4. 04 B2 Upper Intermediate

    making a room or area completely dark by covering windows.

    the act of extinguishing or hiding all lights, historically as a defense against air raids.

    Simple

    We put up blackout curtains so the streetlights wouldn't keep us awake.

    In context

    During the war, strict blackout regulations were enforced to ensure that no light was visible to enemy aircraft from the ground.

  5. 05 C1 Advanced Informal Computing

    when a website is intentionally taken offline to protest against something.

    an intentional, temporary outage of a website or digital service, typically executed as a form of political or social protest.

    Simple

    Several major websites joined the blackout to protest the new internet laws.

    In context

    The digital blackout served as a powerful demonstration of the community's collective influence over the platform's advertising revenue.

The next complete lunar blackout won't be until New Year's Eve 2028, with Asia and Australia at center stage.

Phys.org· 22 Aug 2026

No amount of darkness, earplugs or blackout blinds can entirely silence it.

BBC News· 19 Jul 2026

Deverbal from black out.

Etymology adapted from Wiktionary, available under CC BY-SA 4.0.

This entry
Level B2 · Upper Intermediate
Frequency Frequent
Updated