The Collaborative International Dictionary of English v.0.48:

Elective \E*lect"ive\, a. [Cf. F. ['e]lectif.]
   1. Exerting the power of choice; selecting; as, an elective
      act.
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   2. Pertaining to, or consisting in, choice, or right of
      choosing; electoral.
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            The independent use of their elective franchise.
                                                  --Bancroft.
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   3. Bestowed or passing by election; as, an elective office.
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            Kings of Rome were at first elective; . . . for such
            are the conditions of an elective kingdom. --Dryden.
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   4. Dependent on choice; that can be refused; as, an elective
      college course. Opposite of required or mandatory.
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   Elective affinity or Elective attraction (Chem.), a
      tendency to unite with certain things; chemism.
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