irrecoverable adj.

word-forming element meaning "not, opposite of, without" (also im-, il-, ir- by assimilation of -n- with following consonant, a tendency which began in later Latin), from Latin in- "not," cognate with Greek an-, Old English un-, all from PIE root *ne- "not."

In Old French and Middle English often en-, but most of these forms have not survived in Modern English, and the few that do (enemy, for instance) no longer are felt as negative. The rule of thumb in English has been to use in- with obviously Latin elements, un- with native or nativized ones.

c. 1300, recoveren, "to regain consciousness," also "regain health or strength after sickness, injury, etc.," from Anglo-French rekeverer (13c.), Old French recovrer "come back, return; regain health; procure, get again" (11c.), from Medieval Latin recuperare "to recover" (source of Spanish recobrar, Italian ricoverare; see recuperation).

The sense of "get (anything) back, get or regain possession or control of," literally or figuratively, after it has been lost, is attested from mid-14c. In law, "obtain by judgment or legal proceedings," late 14c. The transitive sense of "restore from sickness, restore (another) to health" is from c. 1600; that of "rescue, save from danger" is from 1610s. Related: Recovered; recovering. To recover arms (1680s) is to bring the piece from the position of "aim" to that of "ready."