seal off

Idioms  

1. Also, seal up. Close tightly or barricade to prevent entry or exit. For example, We're sealing off the unused wing of the building, or The jar is tightly sealed up. Dating from the first half of the 1900s, this idiom uses seal in the sense of “close securely,” as one used to do with a seal of wax.

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Example Sentences

The luxurious hotel complex -- hard to access and therefore easy to seal off -- was proposed by Washington and Tehran as well as their Pakistani and Qatari mediators, Switzerland said Tuesday.

From Barron's • Jun. 16, 2026

Working with Ukrainian authorities, the team from Gloucestershire aims to teach farmers how to seal off areas that are highly contaminated.

From BBC • Mar. 13, 2026

Others questioned whether the Forest Service has the means to enforce such a closure — it’s pretty difficult to physically seal off a mountain.

From Los Angeles Times • Feb. 10, 2026

And it exposes something deeper about how the law handles its most final punishment: its willingness to seal off inquiry precisely when the stakes are highest.

From Slate • Jun. 26, 2025

He was trying to seal off the front of his cell by hanging plastic bags and blankets all over the bars—the smoke was that dense.

From "Newjack: Guarding Sing Sing" by Ted Conover

Related Words

• circle
• enclose
• surround