Containing three replaceable atoms or radicals.(adjective)
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Use "triatomic" in a sentence
"Since that's close to the thickness of ordinary glass, and since CO2, glass, and perspex block IR by the same mechanism, namely absorption by triatomic molecules, if not at the exact same wavelengths, the analogy is an excellent one even quantitatively!"
"Here is an infra-red absorption spectrum of a triatomic molecule."
"Most of the living biomass is water, and this unique triatomic compound is also indispensable for all metabolic processes."