flash point also flash·point (flăshpoint′)
1. The lowest temperature at which a combustible liquid or solid produces sufficient vapor near its surface to generate an ignitable mixture with air.
2. The point at which eruption into significant action, creation, or violence occurs: "The shootdown did not increase international tensions to the flash point" (Seymour M. Hersh).
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.