va·pour (v??p?r)n. & v. Chiefly British Variant of vapor.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.vapour (?ve?p?) or vaporn1. (General Physics) particles of moisture or other substance suspended in air and visible as clouds, smoke, etc2. (General Physics) a gaseous substance at a temperature below its critical temperature. Compare gas33. (General Physics) a substance that is in a gaseous state at a temperature below its boiling point4. rare something fanciful that lacks substance or permanence5. the vapours archaic a depressed mental condition believed originally to be the result of vaporous exhalations from the stomachvb6. (General Physics) to evaporate or cause to evaporate; vaporize7. (intr) to make vain empty boasts; brag[C14: from Latin vapor] ?vapourable, ?vaporable adj ?vapoura?bility, ?vapora?bility n ?vapourer, ?vaporer n ?vapourish, ?vaporish adj ?vapourless, ?vaporless adj ?vapour-?like, ?vapor-?like adj ?vapoury, ?vapory adjCollins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014va?por (?ve? p?r) n. 1. a visible exhalation, as fog or smoke, suspended in the air. 2. a substance in gaseous form that is below its critical temperature. 3. a substance converted into vapor for technical or medicinal uses. 4. a combination of a vaporized substance and air. 5. gaseous particles of drugs that can be inhaled as a therapeutic agent. 6. Archaic. a. a strange, senseless, or fantastic notion. b. something insubstantial. 7. vapors, Archaic. a. mental depression or hypochondria. b. injurious exhalations supposed to be produced within the body, esp. in the stomach. v.i. 8. to rise in the form of vapor. 9. to emit vapor. 10. to talk pompously. Also, esp. Brit., vapour. [1325?75;