irreclaimable (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.

early 14c., reclaimen, "call back a hawk to the glove," from Old French reclamer "to call upon, invoke; claim; seduce; to call back a hawk" (12c., Modern French réclamer) and directly from Latin reclamare "cry out against, contradict, protest, appeal," from re- "opposite, against" (see re-) + clamare "cry out" (from PIE root *kele- (2) "to shout").

"Call out; call back a hawk," hence "make tame" (mid-15c.), "subdue, reduce to obedience, make amenable to control" (late 14c.). Many Middle English senses lack an apparent notion of return or reciprocation (not unusual with Middle English re- words). Meaning "revoke" (a grant, gift, etc.) is from late 15c. That of "recall (someone) from an erring course to a proper state" is from mid-15c.

The sense of "get back by effort" might reflect influence of claim. The specific meaning "bring waste land into useful condition fit for cultivation" is attested by 1764, probably on notion of "reduce to obedience" (perhaps from the image of taming wild animals) rather than a suggestion of a return to a previous condition. Related: Reclaimed; reclaiming.