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Synonyms

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.

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

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

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

If results find contamination, homeowners will probably be left to pay for additional soil removal or other methods to seal off contaminated areas.

From Los Angeles Times • May 9, 2025

The creatures then seal off the burrows at the ground line, where crawfish will survive “so long as there is some water on the bottom of that burrow,” Shirley explains.

From National Geographic • Feb. 15, 2024

We’ll seal off everything except the upper storage room and the tunnels leading in the front and out the back.

From "Mrs. Frisby and the Rats of NIMH" by Robert C. O'Brien

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.