di·ox·ane (d?-?k?s?n?)n. A flammable, potentially explosive, colorless liquid, C4H8O2, that is used as a solvent for fats, greases, and resins and in various products including paints, lacquers, glues, cosmetics, and fumigants.[di- + ox(o)- + -ane.]American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.