Source : Webster's Revised Unabridged Dictionary (1913)

Irretrievable \Ir`re*triev"a*ble\, a.
   Not retrievable; irrecoverable; irreparable; as, an
   irretrievable loss.

   Syn: Irremediable; incurable; irrecoverable.

Source : WordNet®

irretrievable
     adj : impossible to recover or recoup or overcome; "an
           irretrievable loss"; "irretrievable errors in judgment"
           [syn: {unretrievable}]