Meaning of “irreversible” - Learner’s Dictionary

irreversible

adjective uk us /ˌɪrɪˈvɜːsəbl/

Something that is irreversible cannot be changed back to how it was before:

Smoking has caused irreversible damage to his lungs.
irreversibly adverb

(Definition of “irreversible” from the Cambridge Learner’s Dictionary © Cambridge University Press)