In*ac"tive (?), a. [Pref. in- not + active: cf. F. inactif.]

1. Not active; having no power to move; that does not or can not produce results; inert; as, matter is, of itself, inactive.

2. Not disposed to action or effort; not diligent or industrious; not busy; idle; as, an inactive officer.

3. (Chem. & Opt.) 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.

Syn. -- Inert; dull; sluggish; idle; indolent; slothful; lazy. See Inert.

• Not active, temporarily or permanently
       The volcano is inactive, but is only dormant.
  
• Not functioning or operating; broken down
       The photocopier is inactive pending repair.
  
• Retired from duty or service
       Admiral Jones is now on the inactive list.
  
• (chemistry) Relatively inert
       Aluminium is inactive towards water.
  
• (physics) Showing no optical activity in polarized light
       Synthetic glycine is optically inactive as it contains equal amounts of the d- and l- form.