Meaning of “blackout” - Learner’s Dictionary

blackout

noun [ C ] uk us /ˈblækaʊt/
UNCONSCIOUS

the state of being unconscious for a short time

NO INFORMATION

a situation in which people are not allowed to be told about something:

NO ELECTRICITY

a failure in the supply of electricity

NO LIGHTS

a period during a war when no lights must show at night

(Definition of “blackout” from the Cambridge Learner’s Dictionary © Cambridge University Press)