dialysis

noun

di·​al·​y·​sis dī-ˈa-lə-səs How to pronounce dialysis (audio)
plural dialyses dī-ˈa-lə-ˌsēz How to pronounce dialysis (audio)
1
: the separation of substances in solution by means of their unequal diffusion through semipermeable membranes
especially : such a separation of colloids from soluble substances
2
: the process of removing blood from an artery (as of a patient affected with kidney failure), purifying it by dialysis, adding vital substances, and returning it to a vein

called also hemodialysis

dialytic adjective

Examples of dialysis in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
For many people in their 30s and 40s, early detection and the new medications could keep their kidneys healthy enough to stave off dialysis and kidney transplants. Charles Schmidt, Scientific American, 17 Mar. 2026 Johnson's life now depends on dialysis three times a week. Stephanie Stahl, CBS News, 17 Mar. 2026 For animals with severe toxicities, dialysis can be used to treat kidney failure as well as to extract poisonous substances from the blood, preventing further damage. The Washington Post, San Diego Union-Tribune, 14 Mar. 2026 After that operation was completed, Hart resumed dialysis and underwent regular cancer screenings as a result of her exposure to the cancerous donor organ, the lawsuit alleged. Clark Kauffman, Iowa Capital Dispatch, 13 Mar. 2026 See All Example Sentences for dialysis

Word History

Etymology

New Latin, from Greek, separation, from dialyein to dissolve, from dia- + lyein to loosen — more at lose

First Known Use

1861, in the meaning defined at sense 1

Time Traveler
The first known use of dialysis was in 1861

Browse Nearby Words

Cite this Entry

“Dialysis.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/dialysis. Accessed 22 Mar. 2026.

Kids Definition

dialysis

noun
di·​al·​y·​sis dī-ˈal-ə-səs How to pronounce dialysis (audio)
plural dialyses -ə-ˌsēz How to pronounce dialysis (audio)
1
: the separation of substances in solution by means of their unequal diffusion through membranes with pores of a specified maximum size
especially : such a separation of colloids from dissolved substances
2
: the process of removing blood from an artery (as of a patient with failing kidneys), purifying it by dialysis, and returning it to a vein

Medical Definition

dialysis

noun
di·​al·​y·​sis dī-ˈal-ə-səs How to pronounce dialysis (audio)
plural dialyses -ˌsēz How to pronounce dialysis (audio)
1
: the separation of substances in solution by means of their unequal diffusion through semipermeable membranes
especially : such a separation of colloids from soluble substances
2
: either of two medical procedures to remove wastes or toxins from the blood and adjust fluid and electrolyte imbalances by utilizing rates at which substances diffuse through a semipermeable membrane:
a
: the process of removing blood from an artery (as of a kidney patient), purifying it by dialysis, adding vital substances, and returning it to a vein

called also hemodialysis

b
: a procedure performed in the peritoneal cavity in which the peritoneum acts as the semipermeable membrane

called also peritoneal dialysis

dialytic adjective

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