The Oxford Thesaurus An A-Z Dictionary of Synonyms - inert adj.

1) inactive, unreactive, unresponsive, neutral: Argon, xenon, and neon are inert gases. 2) motionless, immobile, inanimate, lifeless, still, quiet, quiescent, stationary, static: He was mute and inert: it was like talking to a zombie. 3 sluggish, slow, torpid, dull, inactive, idle, indolent, lazy, slothful, leaden, slack, passive, supine, dormant, otiose, listless, languid or languorous: I contemplated the inert bodies sunbathing around the swimming-pool.