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

Relapse rates remained low among those who responded, particularly among the strongest responders.

From Science Daily • Jan. 20, 2026

Relapse is generally accepted as a natural part of recovery.

From Los Angeles Times • May 13, 2025

Another song called Relapse on the same album is about "knowing that person was not very good for me".

From BBC • Jan. 19, 2023

Relapse can happen if no other treatment is used during and after ECT.

From Slate • Dec. 21, 2022

Relapse, or a return of the fever and other symptoms all over again, occurs in about ten per cent of the cases.

From The Home Medical Library, Volume I (of VI) by Winslow, Kenelm

Related Words

• recidivism
• recurrence
• regression
• worsening