inert (adj.) Look up inert at Dictionary.com
1640s, from French inerte (16c.) or directly from Latin inertem (nominative iners) "unskilled, inactive, helpless, sluggish, worthless," from in- "without" + ars (genitive artis) "skill" (see art (n.)). Originally of matter; specifically of gases from 1885. Of persons or creatures, from 1774.