re·​flux | \ˈrē-ˌfləks \

Definition of reflux 

(Entry 1 of 2)

1a : a flowing back

b : gastroesophageal reflux

2 : a process of refluxing or condition of being refluxed


re·​flux | \ri-ˈfləks, ˈrē-ˌfləks\
refluxed; refluxing; refluxes

Definition of reflux (Entry 2 of 2)

transitive verb

: to cause to flow back or return especially : to heat such that the vapors formed condense and return to be heated again

intransitive verb

: to flow back

Examples of reflux in a Sentence

Recent Examples on the Web: Noun

Vinegar contains zero calories, enhances flavor, and poses a low health risk, except for acid reflux-sufferers and diabetics. Jaclyn London, Ms, Rd, Cdn, Good Housekeeping, "The Real Benefits of Apple Cider Vinegar, According to a Nutritionist," 21 Nov. 2018 One out of five Americans suffers from gastroesophageal reflux disease, aka GERD or acid reflux. Jill Provost, Woman's Day, "End Digestive Problems for Good," 21 May 2012 And, of course, this is another reason to quit smoking, since the habit can worsen reflux issues. Danielle Sepulveres, SELF, "My Exercise-Induced Acid Reflux Almost Made Me Stop Running," 7 Nov. 2018 Then head to your doctor, as bad breath could be a symptom of various medical conditions such as sinus or lung infections, bronchitis, gastric reflux, a tonsil infection, and even some liver or kidney diseases. Samantha Lefave, Redbook, "Why You Should Never Ignore Sweet-Smelling Urine (or These Other Body Odors)," 3 Aug. 2018 Between gas, constipation and acid reflux, digestive issues are among the most unpleasant ailments—and the touchiest topics to broach. Jill Provost, Woman's Day, "End Digestive Problems for Good," 21 May 2012 The drugs studied were those commonly taken by adults for high blood pressure, acid reflux, pain, and birth control, among others (the authors were careful to exclude adults who were already taking antidepressant medications). Ronald S. Litman,, "Unintended consequences of taking prescription medicines," 20 June 2018 Dental erosion usually happens when too much acid (like from soda, acid reflux, or excessive vomiting damages your teeth over time, the ADA says. Korin Miller, SELF, "5 Reasons Your Teeth Are So Agonizingly Sensitive," 18 Apr. 2018 Acid reflux comes from a diet that is high in sugar. Naseem S. Miller,, "Your child's runny nose may be because of acid reflux," 30 May 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'reflux.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of reflux


15th century, in the meaning defined at sense 1a


1926, in the meaning defined at transitive sense

History and Etymology for reflux


Middle English, from Medieval Latin refluxus, from Latin re- + fluxus flow — more at flux

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Statistics for reflux

Last Updated

14 Dec 2018

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Time Traveler for reflux

The first known use of reflux was in the 15th century

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More Definitions for reflux



English Language Learners Definition of reflux

medical : a backward flow of the contents of the stomach into the esophagus that causes heartburn


re·​flux | \ˈrē-ˌfləks \

Medical Definition of reflux 

(Entry 1 of 3)

1a : a flowing back : regurgitation reflux of gastric acid mitral valve reflux

b : gastroesophageal reflux

2 : a process of refluxing or condition of being refluxed the sample was hydrolyzed…under reflux for 24 hours— T. Y. Ho et al



Medical Definition of reflux (Entry 2 of 3)

: of, relating to, involving, or caused by reflux reflux esophagitis

Medical Definition of reflux (Entry 3 of 3)

: to cause to flow back or return especially : to heat (as under a reflux condenser) so that the vapors formed condense to a liquid that flows back to be heated again

intransitive verb

: to flow back damage to the esophageal mucous membrane when gastric acid refluxed into the esophagus

More from Merriam-Webster on reflux

Rhyming Dictionary: Words that rhyme with reflux Encyclopedia article about reflux

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