Browse all

seal off

B1 neutral separable transitive
In simple words

To completely close an area so nobody can get in or out

Literal meaning: To seal (close completely) something off from the outside — fairly transparent

Meanings

1 B1 neutral

To close an area, building, or street completely, preventing anyone from entering or leaving, usually for safety or security

"Police sealed off the street after reports of a suspicious package."

"Police sealed off a wide area around the Houses of Parliament."

— The Guardian (approximate), reporting on UK security incidents
Grammar: separable
2 B1 neutral

To close a section of a building, system, or structure completely to prevent the spread of something harmful

"Firefighters sealed off the ventilation system to stop the smoke from spreading."

Grammar: separable
3 B2 idiomatic neutral

(Figurative) To cut off access to information, communication, or opportunity

"The new government sealed off all independent media from the official press briefings."

Grammar: separable
Usage notes

Very common in news reports about emergencies, crime scenes, and military operations. Often used with authorities (police, military) as the subject. The 'off' particle emphasises complete separation or disconnection from the outside.

Commonly used with

area building street border zone perimeter

Forms

Base
seal off
I/you/we/they
3rd person
seals off
he/she/it
Past simple
sealed off
yesterday
Past participle
sealed off
have + pp
-ing form
sealing off
continuous

Understand "seal off" better

Try:

Real video examples

Video examples are being collected. Check back soon.

Synonyms

Want to master this phrasal verb?

Practice "seal off" on Looplines