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

Whether it is a renaissance or a relapse depends almost entirely on whether Mourinho has learned anything from the last decade.

From BBC • May 13, 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

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

From Science Daily • Mar. 25, 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

Related Words

• recidivism
• recurrence
• regression
• worsening