The Collaborative International Dictionary of English v.0.48:

Significative \Sig*nif"i*ca*tive\, a. [L. significativus: cf. F.
   significatif.]
   1. Betokening or representing by an external sign.
      [1913 Webster]

            The holy symbols or signs are not barely
            significative.                        --Brerewood.
      [1913 Webster]

   2. Having signification or meaning; expressive of a meaning
      or purpose; significant.
      [1913 Webster]

            Neither in the degrees of kindred they were
            destitute of significative words.     --Camden.
      [1913 Webster] -- Sig*nif"i*ca*tive*ly, adv. --
      Sig*nif"i*ca*tive*ness, n.
      [1913 Webster]

WordNet (r) 3.0 (2006):

significative
    adj 1: (usually followed by `of') pointing out or revealing
           clearly; "actions indicative of fear" [syn: indicative,
           indicatory, revelatory, significative,
           suggestive]