re·​flux | \ ˈrē-ˌfləks How to pronounce reflux (audio) \

Definition of reflux

 (Entry 1 of 2)

1a : a flowing back
2 : a process of refluxing or condition of being refluxed


re·​flux | \ ri-ˈfləks How to pronounce reflux (audio) , 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 Acid reflux is a common problem and being slightly propped up can alleviate those symptoms. Bre Richey,, "The best mattress for pregnancy," 14 Apr. 2021 Risk factors include obesity, smoking, poor diet and chronic acid reflux. Anna Kuchment, Dallas News, "New drug doubles disease-free survival in esophageal cancer," 31 Mar. 2021 Coffee isn't for everyone, including those who suffer from acid reflux, sleep disorders or sleep hygiene concerns, anxiety, or more simply a dietary sensitivity to caffeine. Stefani Sassos, Ms, Rdn, Cso, Good Housekeeping, "12 Ways Coffee May Boost Your Health and Wellness, According to Research," 1 Mar. 2021 These pillows are typically used to help alleviate symptoms of acid reflux, gastroesophageal reflux disease (GERD), and obstructive sleep apnea. Jamie Kim, Good Housekeeping, "Every Type of Pillow You Need to Know About," 18 Feb. 2021 First, there were persistent coughs, and then, a few years later, asthma, sinus inflammation, acid-reflux disease, C.O.P.D., and pneumonia. Brooke Jarvis, The New Yorker, "What Happens When You Breathe," 18 Jan. 2021 Experts say women are more likely to delay seeking care during a heart attack, mistaking symptoms for less life-threatening conditions like acid reflux. Adrianna Rodriguez, USA TODAY, "Women are more likely than men to develop heart failure or die after a heart attack, study says," 30 Nov. 2020 For those with gastrointestinal reflux, more pressure can cause the acid of heartburn. Linda Gandee, cleveland, "Here are some tips to avoid overeating this holiday season," 14 Dec. 2020 Trump’s physician, Dr. Sean Conley, said Friday doctors were providing Trump with an experimental antibody cocktail; vitamin D; famotidine, which is typically used to treat heartburn and acid reflux; the sleep aid melatonin; and an aspirin. Ellen Knickmeyer,, "What we know — and what we don’t — about Trump’s COVID-19 diagnosis and treatment," 2 Oct. 2020 Recent Examples on the Web: Verb On recalling Zantac What to do for the fizzle and roil When refluxing guts sour and spoil? Meghana Keshavan, STAT, "2019 in limericks: The highs and lows from the life sciences," 31 Dec. 2019

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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Time Traveler for reflux

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

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Last Updated

18 Apr 2021

Cite this Entry

“Reflux.” Dictionary, Merriam-Webster, Accessed 10 May. 2021.

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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 How to pronounce reflux (audio) \

Medical Definition of reflux

 (Entry 1 of 3)

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

Thesaurus: All synonyms and antonyms for reflux Encyclopedia article about reflux

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