Definition of bar verb from the Oxford Advanced American Dictionary

Oxford3000

bar

verb
/bɑr/
 
 
barring, barred

close with bars

1 [usually passive] bar something to close something with a bar or barsAll the doors and windows were barred.

block

2 bar something to block a road, path, etc. so that no one can passTwo police officers were barring her exit.We found our way barred by rocks.

prevent

3 bar someone (from something/from doing something) to ban or prevent someone from doing somethingAsylum seekers are barred from entering the country.
IDIOM

no holds barred

with no rules or limits on what someone is allowed to do
There will be no holds barred in his interview with the president this evening.no holds barred