re·flux (r??fl?ks?)n.1. A flowing back; ebb.2. Medicine Backflow, as of gastric acid into the esophagus.3. Chemistry The process of refluxing.v. re·fluxed, re·flux·ing, re·flux·es Chemistry v.tr. To boil (a liquid) in a vessel attached to a condenser so that the vapors continuously condense for reboiling.v.intr. To be boiled in such a way.[Medieval Latin refl?xus : Latin re-, re- + Latin fl?xus, flow, from past participle of fluere, to flow; see bhleu- in Indo-European roots.]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.reflux (?ri?fl?ks) vb (Chemistry) chem to boil or be boiled in a vessel attached to a condenser, so that the vapour condenses and flows back into the vesseln1. (Chemistry) chem a. an act of refluxingb. (as modifier): a reflux condenser. 2. the act or an instance of flowing back; ebb[C15: from Medieval Latin refluxus, from Latin refluere to flow back]Collins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014re?flux (?ri?fl?ks) n. a flowing back; ebb. [1400?50; late Middle English