having no inherent power of action, motion, or resistance ( opposed to active )

inert matter.

Chemistry . having little or no ability to react, as nitrogen that occurs uncombined in the atmosphere.

Pharmacology . having no pharmacological action, as the excipient of a pill.

inactive or sluggish by habit or nature.

adjective

active , alive , animated , lively , mobile , moving , working

adjective

apathetic , asleep , dead , dormant , down , dull , idle , immobile , impassive , impotent , inactive , inanimate , indolent , languid , languorous , lazy , leaden , listless , motionless , numb , paralyzed , passive , phlegmatic , powerless , quiescent , quiet , slack , sleepy , slothful , sluggard , sluggish , slumberous , static , still , stolid , torpid , unmoving , unreactive , unresponsive , inoperative , lethargic , lifeless , neutral , slow , stationary , supine