The phrasal verb "block off" is predominantly used in informal to semi-formal speech and writing, though it may appear in more formal contexts such as in technical or logistical communications. It generally means to close a space or prevent access to an area by using barriers or by some other means of obstruction. Common contexts for its use include city planning or construction contexts where roads may be blocked off for repairs, emergency services blocking off sections for safety reasons, or events requiring certain areas to be restricted to unauthorized personnel or traffic. This phrasal verb sees frequent utilization in real-time reporting, administrative announcements, and security briefings. The term implies a temporariness in most uses, indicating a reversible action meant to temporarily alter usual access patterns.
B1
PreIntermediate
1. To close or seal a path or entrance so that people or things cannot pass through.
The police blocked off the main street due to the parade.
Workers blocked off the entrance while they carried out repairs.
2. To put an object or structure in place to stop movement or access.
He blocked off the door with a heavy chair to prevent anyone from entering.
The floodwaters rose, blocking off roads in the area.
