intransitive verb
1.
a. : to turn off the stage lighting in order to indicate the end of a theatrical performance or of a scene in a play
b. : to become enveloped in darkness
as the heroine speaks this line the scene blacks out
astronomers have observed that stars sometimes black out
2.
a. : to undergo a transient dulling or loss of vision or consciousness as a result of temporary impairment of cerebral circulation or retinal anoxia, traumatic emotional blows, or an alcoholic bout
an airplane pilot may black out while pulling out of a dive
b. : to have a lapse of memory
c. : to lose consciousness
became ill and blacked out behind the wheel — Springfield (Massachusetts) Union
3.
a. : to make an object or area invisible or less conspicuous by extinguishing or screening all lights for protection especially against air attack
my orders are to black out at sunset
b. : to become invisible or less conspicuous by the extinguishing or screening of all lights for protection especially against air attack : become blacked out
I have a truck to sleep in … It can … black out, and has a huge map board so one can work at night — G.S.Patton
4. : to become inoperative or ineffectual : cease to exist or act
shortwave radio transmission blacked out because of a sunspot
telephones blacked out over a wide area
transitive verb
1.
a. : to envelop in darkness
power failure blacked out the city
especially : to make (an object or area) invisible or less conspicuous by extinguishing or screening all lights for protection against air attack
the city was blacked out
b. : to extinguish or screen especially in order to make an object or area invisible or less conspicuous for protection against air attack
the lights were blacked out
we had to black out all our windows
c. : to debar from transmitting or receiving information and ideas
a nation that had been blacked out from the rest of the world — Sigrid Arne
2. : to silence or jam (radio transmission) effectively
3. : to make inoperative, ineffectual, or temporarily nonexistent or insignificant : destroy
falling trees blacked out several electric power lines
some intercollegiate sports were blacked out by the war
the newspaper was blacked out by insolvency
relief emergencies … must not black out the longer task of recovery — Air Transport
4. : to cause (a person) to undergo transient dulling or loss of vision or consciousness
the first drag at the cigarette had nearly blacked him out — J.A.Phillips
5. : to restrict or forbid the telecasting of (a program to which admission is charged) especially in the area of origination in order to protect gate receipts
a program blacked out in the city
: prohibit such telecasting in
the city is blacked out for this game