tr.v. ni·tri·fied, ni·tri·fy·ing, ni·tri·fies
1. To oxidize (an ammonia compound) into a nitrite or (a nitrite) into a nitrate, especially by the action of nitrifying bacteria.
2. To treat or combine with nitrogen or compounds containing nitrogen.
ni′tri·fi·cation (-fĭ-kāshən) n.
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2019 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.