Source : Webster's Revised Unabridged Dictionary (1913)

Inactive \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}.

Source : WordNet®

inactive
     adj 1: not participating in a chemical reaction; "desired amounts
            of inactive chlorine"
     2: not progressing or increasing; or progressing slowly [ant: {active}]
     3: not active or exerting influence [ant: {active}]
     4: of e.g. volcanos; permanently inactive; "an extinct volcano"
        [syn: {extinct}] [ant: {active}, {dormant}]
     5: of e.g. volcanos; temporarily inactive; "a dormant volcano"
        [syn: {dormant}] [ant: {extinct}, {active}]
     6: lacking in energy or will; "Much benevolence of the passive
        order may be traced to a disinclination to inflict pain
        upon oneself"- George Meredith [syn: {passive}] [ant: {active}]
     7: lacking activity; lying idle or unused; "an inactive mine";
        "inactive accounts"; "inactive machinery" [ant: {active}]
     8: not engaged in full-time work; "inactive reserve" ; "an
        inactive member of the department" [ant: {active}]
     9: not active physically or mentally; "illness forced him to
        live an inactive life"; "dreamy and inactive by nature"
        [ant: {active}]
     10: not engaged in military action [syn: {reserve(a)}]
     11: not in physical motion; "the inertia of an object at rest"
         [syn: {motionless}, {static}, {still}]
     12: temporarily inactive [syn: {abeyant}, {in abeyance(p)}, {suspended}]