irreversible

Unable to return to the condition that existed before a change.

• The fire caused irreversible damage.
• The disease can lead to irreversible hearing loss.
• Some changes to the landscape are irreversible.

Similar words: permanent, lasting

Opposites: reversible

Common phrases: irreversible damage, irreversible change, irreversible loss

Unable to be canceled or undone once it has happened or been decided.

• This decision is irreversible.
• Signing the agreement was an irreversible step.
• Consider the consequences before making an irreversible commitment.

Similar words: irrevocable, final

Opposites: reversible

Common phrases: irreversible decision, irreversible step, irreversible commitment

Describing a physical process that cannot be fully reversed without using energy and increasing disorder.

• Friction makes the process irreversible.
• The gas underwent an irreversible expansion.
• An irreversible process increases the total entropy of the system and its surroundings.

Opposites: reversible

Common phrases: irreversible process, irreversible expansion, irreversible heat transfer

Unable to move or operate in the opposite direction.

• The mechanism is irreversible.
• They installed an irreversible gear to prevent backward movement.
• This irreversible engine cannot run in the opposite direction.

Similar words: nonreversible

Opposites: reversible

Common phrases: irreversible engine, irreversible gear, irreversible mechanism