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reflux Line breaks: re¦flux
Pronunciation: /ˈriːflʌks/

Definition of reflux in English:


[mass noun]
1 Chemistry The process of boiling a liquid so that any vapour is liquefied and returned to the stock: the mixture was heated at reflux under nitrogen
More example sentences
  • They looked at various substituted benzaldehydes and cyanoamides and compared the results of traditional ethanol reflux, water reflux and solvent-free conditions.
  • In general, distillation can be carried out either with or without reflux.
  • Sugar concentrations in the tips were measured after extraction two times in 4 ml of 80% ethanol boiled with reflux for 20 min.
2 technical The flowing back of a liquid, especially that of a fluid in the body: lying down tends to promote acid reflux [as modifier]: patients with reflux oesophagitis
More example sentences
  • Most investigators consider any esophageal pH below 4.0 as the cutoff defining reflux of gastric acid into the esophagus.
  • I would not have diagnosed reflux on the basis of those records.
  • Just doors away on the same street, Paul Samuels suffered numerous urinary infections and was also diagnosed with the same reflux as the Buckley and Chapman children.


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1 [no object] Chemistry Boil or cause to boil in circumstances such that the vapour returns to the stock of liquid after condensing: [no object]: the liquid is allowed to reflux until the thermometer records the lowest temperature possible [with object]: the solutions were refluxed for 9-12 hours
More example sentences
  • Second, the alkaloid is refluxed with acetic anhydride for about five hours.
  • In the laboratory higher concentration ethanol, with less water, can be produced by refluxing the rectified spirit with quicklime and then distilling the alcohol mixture.
  • Three liters of 95% ethanol were added to each bottle and then refluxed for 4 hours.
2 [no object, with adverbial of direction] technical (Of a liquid, especially a bodily fluid) flow back: acidic secretions of the stomach can reflux back upwards
More example sentences
  • The reflex peristaltic contraction sweeps any refluxed gastric fluid back into the stomach.
  • The main function of pyloric closure is to reduce the volume of fluid that refluxes into the distal stomach from the duodenum.
  • Gastro-oesophageal reflux disease is defined as symptoms or mucosal damage resulting from the exposure of the distal oesophagus to refluxed gastric contents.


Middle English: from re- and flux.

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