pneu·mo·co·ni·o·sis (n′mō-kō′nē-ōsĭs, ny′-)
Any of several, usually occupational diseases of the lungs, such as asbestosis or silicosis, caused by prolonged inhalation of especially mineral or metallic dust particles.
pneu′mo·co′ni·otic (-ŏtĭk) adj. & n.
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.