Incapable of being brought back or remedied

जिसे वापस लाना असंभव है

English Usage: Once the opportunity was missed, it became irretrievable.

Hindi Usage: एक बार अवसर चूक जाने पर, वह वापस नहीं लिया जा सकता था।

Something that cannot be regained or recovered

जो पुनः प्राप्त नहीं किया जा सकता

English Usage: After the accident, the data was deemed irretrievable.

Hindi Usage: दुर्घटना के बाद, डेटा को अपरिवर्तनीय माना गया।