relapse

American  

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

verb (used without object)

relapsed, relapsing

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

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noun

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

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noun

1. the act or an instance of relapsing

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

Other Word Forms

• relapsable
  adjective
• relapser
  noun
• unrelapsing
  adjective

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

Now, after 33 months of follow-up, none of the patients have experienced a relapse.

From Science Daily • May 6, 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

Looking to the future, George said he planned to continue his treatment to ward off a relapse, but knows that "MS will take what it wants".

From BBC • Mar. 19, 2026

The stories in Lauren Groff’s third collection, “Brawler,” largely feature people who’ve hit crisis points in their lives: the abusive partner, the natural disaster, the relapse, the deathbed.

From Los Angeles Times • Feb. 26, 2026

He’s suffered a relapse, I thought; he is back in his delirium.

From "Z for Zachariah" by Robert C. O’Brien

Related Words

• recidivism
• recurrence
• regression
• worsening