a. Bitingly sarcastic: mordant satire.
b. Incisive and trenchant: an inquisitor's mordant questioning.
2. Bitingly painful.
3. Serving to fix colors in dyeing.
1. A reagent, such as tannic acid, that fixes dyes to cells, tissues, or textiles or other materials.
2. A corrosive substance, such as an acid, used in etching.
tr.v. mor·dant·ed, mor·dant·ing, mor·dants
To treat with a mordant.
[French, from Old French, present participle of mordre, to bite, from Vulgar Latin *mordere, from Latin mordēre; see mer- in the Appendix of Indo-European roots.]
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2020 by Houghton Mifflin Harcourt Publishing Company. 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.