1 British EnglishBEL
if a trade union blacks goods or a company, it refuses to work with them:
The union has blacked all non-urgent work.
to make something black
black outphrasal verb
to become unconscious [= faint, pass out]:
For a few seconds, he thought he was going to black out.
to put a dark mark over something so that it cannot be seen:
The censors had blacked out several words.
to hide or turn off all the lights in a town or city, especially during war
black something ↔ out