A compound with two oxygen atoms per molecule.(noun)
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 "dioxide" in a sentence
"Any further increases of CO2 in the atmosphere will have minimal, if not negligible, effects on the temperature (see "Carbon dioxide is already absorbing almost all it can")."
"The YeZ is a concept car designed to photosynthesize carbon dioxide from the air, much like a plant."
"And carbon dioxide is the predominant greenhouse gas."