The Collaborative International Dictionary of English v.0.48:

Initiative \In*i"ti*a*tive\, a. [Cf. F. initiatif.]
   Serving to initiate; inceptive; initiatory; introductory;
   preliminary.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Initiative \In*i"ti*a*tive\, n. [Cf. F. initiative.]
   1. An introductory step or movement; an act which originates
      or begins.
      [1913 Webster]

            The undeveloped initiatives of good things to come.
                                                  --I. Taylor.
      [1913 Webster]

   2. The right or power to introduce a new measure or course of
      action, as in legislation; as, the initiative in respect
      to revenue bills is in the House of Representatives.
      [1913 Webster]

   3. (Political Science) The right or procedure by which
      legislation may be introduced or enacted directly by the
      people, as in the Swiss Confederation and in many of the
      States of the United States; -- chiefly used with the. The
      procedure of the initiative is essentially as follows:
      Upon the filing of a petition signed by a required number
      or percentage of qualified voters the desired measure must
      be submitted to a popular vote, and upon receiving the
      required majority (commonly a majority of those voting on
      the measure submitted) it becomes a law. In some States of
      the United States the initiative is only local; in others
      it is state-wide and includes the making of constitutional
      amendments.
      [Webster 1913 Suppl.]

   4. a character trait manifested in a readiness and ability to
      initiate action; an enterprising spirit; a go-getting
      attitude; energy; drive; get-up-and-go.
      [PJC]

   5. in interactive activities, such as conversation or games,
      the right or opportunity to set the course of action; as,
      to have the initiative.
      [PJC]

WordNet (r) 3.0 (2006):

initiative
    adj 1: serving to set in motion; "the magazine's inaugural
           issue"; "the initiative phase in the negotiations"; "an
           initiatory step toward a treaty"; "his first (or maiden)
           speech in Congress"; "the liner's maiden voyage" [syn:
           inaugural, initiative, initiatory, first,
           maiden]
    n 1: readiness to embark on bold new ventures [syn:
         enterprise, enterprisingness, initiative, go-ahead]
    2: the first of a series of actions [syn: first step,
       initiative, opening move, opening]

Moby Thesaurus II by Grady Ward, 1.0:

133 Moby Thesaurus words for "initiative":
   abecedarian, aboriginal, adventuresomeness, adventurousness,
   aggression, aggressiveness, alpha, ambition, ambitiousness,
   antenatal, autochthonous, bang, baptismal, beginning, breaking-in,
   budding, constitutional referendum, creative, dash,
   direct initiative, drive, dynamism, elan, elemental, elementary,
   embryonic, energy, enterprise, enterprisingness,
   facultative referendum, fetal, fire, first, first blush,
   first glance, first impression, first inning, first lap,
   first move, first round, first sight, first stage, first step,
   force, forcefulness, formative, foundational, fundamental, gambit,
   gestatory, get-up-and-get, get-up-and-go, getup, ginger, go,
   go-ahead, go-getting, go-to-itiveness, gumption, hustle, in embryo,
   in its infancy, in the bud, inaugural, inceptive, inchoate,
   inchoative, incipient, incunabular, indirect initiative, infant,
   infantile, initial, initiatory, introductive, introductory,
   inventive, kick, le premier pas, lead, leadership, mandate,
   mandatory referendum, nascent, natal, opening move, original,
   parturient, pep, pepper, piss and vinegar, pizzazz, plebiscite,
   plebiscitum, poop, postnatal, pregnant, prenatal, primal, primary,
   prime, primeval, primitive, primitiveness, primitivity,
   primogenial, procreative, punch, push, pushfulness, pushiness,
   pushingness, recall, referendum, resourcefulness, rudimental,
   rudimentary, snap, spirit, spunk, starch, statutory referendum,
   thrust, up-and-comingness, ur, venturesomeness, venturousness,
   verve, vigor, vim, warming-up, zing, zip



Bouvier's Law Dictionary, Revised 6th Ed (1856):

INITIATIVE, French law. The name given to the important prerogative given by
the charte constitutionelle, art. 16, to the late king to propose through
his ministers projects of laws. 1 Toull. n. 39. See Veto.