- The definition of irreversible is something that cannot be altered, changed or undone.
Having your tonsils permanently removed is an example of an irreversible operation.
irreversible definition by Webster's New World
not reversible; specif.,
- that cannot be repealed or annulled
- that cannot be turned inside out, run backward, etc.
irreversible definition by American Heritage Dictionary
Impossible to reverse: an irreversible momentum toward open revolution.
- irˌre·versˌi·bilˈi·ty, irˌre·versˈi·ble·ness noun
- irˌre·versˈi·bly adverb