Source : Webster's Revised Unabridged Dictionary (1913)

Instead \In*stead"\, adv. [Pref. in- + stead place.]
   1. In the place or room; -- usually followed by of.

            Let thistles grow of wheat.           --Job xxxi.
                                                  40.

            Absalom made Amasa captain of the host instead of
            Joab.                                 --2 Sam. xvii.
                                                  25.

   2. Equivalent; equal to; -- usually with of. [R.]

            This very consideration to a wise man is instead of
            a thousand arguments, to satisfy him, that in those
            times no such thing was believed.     --Tillotson.

Source : WordNet®

instead
     adv 1: in place of, or as an alternative to; "Felix became a
            herpetologist instead"; "alternatively we could buy a
            used car" [syn: {alternatively}, {as an alternative},
            {or else}]
     2: on the contrary; "rather than disappoint the children, he
        did two quick tricks before he left"; "he didn't call;
        rather (or instead), he wrote her a letter"; "used English
        terms instead of Latin ones" [syn: {rather}]