unfixable
Definitions
Impossible to repair, mend, or restore to a functional state.
Incapable of being resolved, corrected, or set right.
Examples
The mechanic told me that the damage to the engine was unfixable and I would need to buy a new car.
Some people believe that a broken trust is an unfixable flaw in any relationship.
Synonyms
irreparable irretrievable hopeless incurable irredeemable beyond repair