irretrievable (adj.)
- ablated
- changeless
- constant
- consumed
- depleted
- dissipated
- eroded
- expended
- forfeit
- forfeited
- gone
- immutable
- incommutable
- inconvertible
- incorrigible
- incurable
- indefeasible
- inert
- inoperable
- invariable
- irreclaimable
- irrecoverable
- irredeemable
- irremediable
- irreparable
- irreversible
- irrevocable
- lasting
- lost
- noble
- nonreturnable
- nonreversible
- permanent
- ruined
- shrunken
- squandered
- terminal
- unalterable
- unaltered
- unchangeable
- unchanged
- unchanging
- uncorrectable
- undeviating
- undone
- unmitigable
- unmodifiable
- unremitting
- unsusceptible
- unvarying
- used
- wasted
