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Synonyms

irreversible

American  
[ir-i-vur-suh-buhl] / ˌɪr ɪˈvɜr sə bəl /

adjective

  1. not reversible; incapable of being changed.

    His refusal is irreversible.


irreversible British  
/ ˌɪrɪˈvɜːsəbəl /

adjective

  1. not able to be reversed

    the irreversible flow of time

  2. not able to be revoked or repealed; irrevocable

  3. chem physics capable of changing or producing a change in one direction only

    an irreversible reaction

  4. thermodynamics (of a change, process, etc) occurring through a number of intermediate states that are not all in thermodynamic equilibrium

"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

Other Word Forms

Etymology

Origin of irreversible

First recorded in 1620–30; ir- 2 + reversible

Explanation

If you can't undo something, it's irreversible. Time is always irreversible, as is the damage done to your skin by too much sun, so be sure to wear sunblock! While you see reverse inside of this word, you wouldn't use it to describe a car that can't go backwards. However, if the car was in an accident and cannot be fixed, you could say that the damage done to the car was pretty much irreversible, in other words the car is totaled.

Keep Reading on Vocabulary.com

Vocabulary lists containing irreversible

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:

Because action enters a web of other lives, its consequences are unpredictable and irreversible.

From The Wall Street Journal Aug. 7, 2026

Such a system could help scientists evaluate tissue integrity before major structural damage becomes irreversible.

From Science Daily Jul. 20, 2026

Some experts had voiced concerns that the complicated transfer -- funded by the UK for an undisclosed amount -- risked causing irreversible damage to a work already weakened by 30 tears and nearly 10,000 holes.

From Barron's Jul. 9, 2026

Regenxbio’s Navsunli therapy targets Hunter syndrome, a rare genetic disease that causes irreversible brain damage and cell death, usually leading to death in a patient’s midteens.

From The Wall Street Journal Jun. 22, 2026

Discoveries are moments in an historical process that is intended to be irreversible.

From "The Invention of Science" by David Wootton

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