irretrievable
Definitions
Impossible to regain, recover, or get back.
Unable to be remedied or rectified; irreparable.
Examples
The ancient documents were lost in the fire, rendering their historical contents irretrievable.
Once the deadline has passed, the opportunity to submit your application becomes irretrievable.
Synonyms
irrecoverable irreparable lost gone forever irreversible unrecoverable permanent
Antonyms
recoverable retrievable restorable reclaimable salvageable reversible fixable