not active; having no power to move; that does not or can not produce results; inert; as, matter is, of itself, inactive.-not disposed to action or effort; not diligent or industrious; not busy; idle; as, an inactive officer.-not active; inert; esp., not exhibiting any action or activity on polarized light; optically neutral; -- said of isomeric forms of certain substances, in distinction from other forms which are optically active; as, racemic acid is an inactive tartaric acid.