irreversible

[ ir-i-vur-suh-buhl ]

adjective

1. not reversible; incapable of being changed:

   His refusal is irreversible.

irreversible

/ 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 not able to be revoked or repealed; irrevocable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

Derived Forms

• ˌirreˌversiˈbility, noun
• ˌirreˈversibly, adverb

Other Words From

• irre·versi·bili·ty irre·versi·ble·ness noun
• irre·versi·bly adverb

Word History and Origins

Origin of irreversible¹

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

Example Sentences

“The science on climate change is unforgiving, with every year of delay locking in more costs and more irreversible changes, and everyday people paying the steepest price.”

From Salon

Last year Unesco said the city should be added to a list of world heritage sites in danger, as the impact of climate change and mass tourism threaten to cause irreversible changes to it.

From BBC

The 2023 law, however, bans abortions after six weeks only when they’re “necessary to save the pregnant woman’s life or avert a serious risk of ... irreversible physical impairment” of the pregnant woman.

From Los Angeles Times

There is no cure for the disease, and paralysis caused by an infection is irreversible.

From BBC

When ingested by children, the heavy metal can cause irreversible brain damage and behavioral issues.

From Los Angeles Times

Related Words

• inevitable
• permanent