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relapse

American  
[ri-laps, ri-laps, ree-laps] / rɪˈlæps, rɪˈlæps, ˈri læps /

verb (used without object)

  • relapses,
    present (3rd person singular)
  • relapsed,
    past participle,  past
  • relapsing
    present participle
  1. to fall or slip back into a former state, practice, etc..

    to relapse into silence.

  2. to fall back into illness after convalescence or apparent recovery.

  3. to fall back into vice, wrongdoing, or error; backslide.

    to relapse into heresy.

    Synonyms:
    lapse, revert, regress

noun

  • relapses
    plural
  1. an act or instance of relapsing.

  2. a return of a disease or illness after partial recovery from it.

relapse British  

verb

  1. to lapse back into a former state or condition, esp one involving bad habits

  2. to become ill again after apparent recovery

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

noun

  1. the act or an instance of relapsing

  2. the return of ill health after an apparent or partial recovery

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

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Etymology

Origin of relapse

First recorded in 1400–50; (for the verb) late Middle English, from Latin relāpsus “slid back,” past participle of relābī “to slide back, revert,” from re- re- + lābī “to fall, slide, make a mistake”; noun derivative of the verb

Explanation

A relapse is a decline, especially of someone's health. If your grandmother survived cancer only to have it return two years later, you could say she suffered a relapse. Relapse implies that someone has recovered from an illness and slid back into a worse state, like when you are getting over a cold but then you suddenly feel bad all over again. Unwanted behavior can also be described this way; if you find yourself biting your nails again, it's a nail-biting relapse. The Latin word relabi is the root of relapse, slip back.

Keep Reading on Vocabulary.com

Vocabulary lists containing relapse

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

See Examples For:

The illness is characterized by discomfort, and while it can be frustrating when symptoms relapse, it’s not life-threatening for most people, according to the CDC.

From MarketWatch Jul. 14, 2026

Around 6.7 million people in the U.S. and 160 million worldwide develop the condition in their lifetime, but current therapies for alopecia have high relapse rates, Nektar said.

From Barron's Apr. 20, 2026

Most patients experience a relapse, followed by rapid disease progression.

From Science Daily Mar. 25, 2026

However, while the treatment he receives is effective at preventing another relapse, he still faces problems from the damage that has already been done to his central nervous system.

From BBC Mar. 19, 2026

I returned it to her; she received it quietly, and without saying anything she was about to relapse into her former studious mood: again I ventured to disturb her—

From "Jane Eyre" by Charlotte Brontë

The European Commission approved Cenrifki for secondary progressive multiple sclerosis without relapses.

From The Wall Street Journal Jun. 23, 2026

"If a patient relapses and needs another hospital admission, that's costly too," Mons points out.

From Science Daily Mar. 11, 2026

If a patient relapses or breaks a rule in a rehab facility, the knee-jerk impulse should not be to discharge them from the program.

From Slate Dec. 19, 2025

She’s not sure how her policy on relapses fits in.

From Los Angeles Times May 13, 2025

Sometimes, when I have relapses of my old demon, I lie in the crook of his arm and he comforts me this way, talking to me all night long to stave off the bad dreams.

From "The Poisonwood Bible" by Barbara Kingsolver

After her condition relapsed before joining OpenAI, Simo decided to work remotely from Southern California.

From The Wall Street Journal Apr. 3, 2026

The Food and Drug Administration has accepted a biologics license application for anito-cel as a fourth-line treatment for patients with relapsed or refractory multiple myeloma.

From Barron's Feb. 23, 2026

Her MS hasn’t relapsed in a while, but she has limited sensation in her hands, feet and ankles, and says she sometimes has trouble with her short-term memory.

From Los Angeles Times Mar. 9, 2025

He got off his sick bed to score in a 4-1 victory over Crewe to round off the season, but then relapsed and suffered with pneumonia, which eventually killed him.

From BBC Nov. 1, 2024

The effort succeeded; for an instant he unconsciously relapsed into his old servile manner, bent low before me, and actually fawned upon me as he replied:—

From "Dracula" by Bram Stoker

This approach revealed traces of ancient pathogens, including the plague bacterium Yersinia pestis and the organism responsible for louse-borne relapsing fever, Borrelia recurrentis.

From Science Daily Apr. 22, 2026

Almost a decade later, the Times looks to be relapsing into bad form.

From Salon Apr. 6, 2026

Jebb emphasised that GLP-1 drugs "are a really valuable tool in obesity treatment -- but obesity is a chronic relapsing condition."

From Barron's Jan. 7, 2026

The Swiss pharmaceutical group said Monday that fenebrutinib met its primary endpoint in a Phase 3 clinical trial in patients with relapsing multiple sclerosis, the most common form of the disease.

From The Wall Street Journal Nov. 10, 2025

She remained abed ten years, gradually growing better, but never completely recovering, relapsing periodically into her paralytic state.

From "Black Boy" by Richard Wright

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