Origin and history of inanimate

1590s, "action of imparting life" (a sense now obsolete), from Latin animationem (nominative animatio) "an animating," noun of action from past-participle stem of animare "give breath to," also "to endow with a particular spirit, to give courage to, enliven," from anima "life, breath" (from PIE root *ane- "to breathe").

The meaning "vitality, appearance of activity or life" is from 1610s (the sense in suspended animation, for which see suspended). The cinematographic sense, "production of moving cartoon pictures" is from 1912.

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.