Brick up Definition 1 of 2Pro Tip 1/3Literal Usage Used when physically blocking an opening with bricks, not metaphorically. They bricked up the fireplace to prevent drafts. Pro Tip 2/3Permanent Action Suggests a permanent or long-term closure, not easily reversible. The city bricked up the old tunnel entrance. Pro Tip 3/3Security Measure Often done for security reasons, to prevent entry or passage. To increase safety, they bricked up the backdoor.