Definition of “bar” - Learner’s Dictionary

bar

verb [ T ] uk us /bɑːr/ (present participle barring, past tense and past participle barred)
PREVENT

to officially prevent someone from doing something or going somewhere, or to prevent something from happening:

The government barred demonstrations during the state visit.
KEEP OUT

to stop someone going into a place:

A line of policemen barred the entrance to the camp.
CLOSE

to close and lock a door or gate

(Definition of “bar verb” from the Cambridge Learner's Dictionary © Cambridge University Press)