1. A fireproof wall used as a barrier to prevent the spread of fire.
2. Computers A software program or hardware device that restricts communication between a private network or computer system and outside networks.
intr.v. fire·walled, fire·wall·ing, fire·walls
To protect (a computer or computer network) by means of a firewall.
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2022 by HarperCollins Publishers. All rights reserved.
Indo-European & Semitic Roots Appendices
Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:
The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.