Source : Webster's Revised Unabridged Dictionary (1913)

Elective \E*lect"ive\, n.
   In an American college, an optional study or course of study.
   [Colloq.]

Elective \E*lect"ive\, a. [Cf. F. ['e]lectif.]
   1. Exerting the power of choice; selecting; as, an elective
      act.

   2. Pertaining to, or consisting in, choice, or right of
      choosing; electoral.

            The independent use of their elective franchise.
                                                  --Bancroft.

   3. Dependent on choice; bestowed or passing by election; as,
      an elective study; an elective office.

            Kings of Rome were at first elective; . . . for such
            are the conditions of an elective kingdom. --Dryden.

   {Elective affinity} or {attraction} (Chem.), a tendency to
      unite with certain things; chemism.

Source : WordNet®

elective
     adj 1: subject to popular election; "elective official" [syn: {elected}]
            [ant: {appointive}]
     2: not compulsory; "elective surgery"; "an elective course of
        study"