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

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.
Walker spent years on dialysis, dependent on oxygen and relearning basic motor skills. Candace McKnight, The Orlando Sentinel, 25 July 2026 Though none of them passed, the dialysis industry spent hundreds of millions between 2018 and 2022 to defeat them. Los Angeles Times, 8 July 2026 The former actress and model was previously placed on dialysis and hospitalized at UCLA in Los Angeles for complications from a 2017 transplant. Jaeden Pinder, Rolling Stone, 8 July 2026 The condition leads to progressive loss of kidney function and potentially organ failure requiring dialysis. Adam Feuerstein, STAT, 7 July 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 29 Jul. 2026.

Kids Definition

dialysis

noun
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
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

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