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

---

noun

1. the act or an instance of relapsing

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

Other Word Forms

Derived Forms

• relapser
  noun
• relapsable
  adjective
• unrelapsing
  adjective

Inflected Forms

Nouns

• relapses
  plural

Participles

• relapsing
  present
• relapsed
  past

Conjugated Forms

Present

• relapse
  simple
• relapses
  simple
• have relapsed
  perfect
• has relapsed
  perfect
• am relapsing
  progressive
• are relapsing
  progressive
• is relapsing
  progressive
• have been relapsing
  perfect progressive
• has been relapsing
  perfect progressive

Past

• relapsed
  simple
• had relapsed
  perfect
• was relapsing
  progressive
• were relapsing
  progressive
• had been relapsing
  perfect progressive

Future

• will relapse
  simple
• will have relapsed
  perfect
• will be relapsing
  progressive
• will have been relapsing
  perfect progressive

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.

Example Sentences

See Examples For:

relapse relapses relapsed relapsing

Researchers found there was no significant difference in whether a patient had a relapse of their illness.

From BBC ● Aug. 26, 2026

“As it gets higher stage, the risk of relapse gets higher,” said Michael Atkins, a researcher for the Phase 2 trial and deputy director of the Lombardi cancer center.

From MarketWatch ● Aug. 20, 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

But she experienced a relapse of a neuroimmune condition shortly before joining the company last August, prompting her to work remotely from her home in Southern California.

From The Wall Street Journal ● Apr. 17, 2026

Each instant he seemed as though he would open his eyes and speak; but then would follow a prolonged stertorous breath, and he would relapse into a more fixed insensibility.

From "Dracula" by Bram Stoker

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

Borg admits to several relapses during the 1990s when he also made an abbreviated tennis comeback.

From Los Angeles Times ● Sep. 18, 2025

I wonder if my relapses into depression would happen anyway, or if they are a side effect of menopause.

From Slate ● Jun. 14, 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

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

But in 2017 she relapsed, with Ms Tucker saying at this stage the tumour "eventually took over".

From BBC ● Dec. 3, 2025

Individuals who had relapsed after therapy had significantly narrower cristae than newly diagnosed patients, with the most dramatic differences appearing in those previously treated with venetoclax.

From Science Daily ● Nov. 23, 2025

To the insurer, it would look like he had relapsed, which he said he had not during that time.

From The Wall Street Journal ● Oct. 9, 2025

He braced himself before entering his dad’s room, fearing he might have relapsed, but when he went in, a happy scene awaited him.

From "Gregor the Overlander" by Suzanne Collins

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

But now, almost a decade later, the Times looks to be relapsing into bad form.

From Salon ● Apr. 6, 2026

“Obesity is a chronic, relapsing, biologically defended disease,” says Stanford.

From The Wall Street Journal ● Mar. 16, 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

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

From "Black Boy" by Richard Wright

Related Words

• recidivism
• recurrence
• regression
• worsening