The Collaborative International Dictionary of English v.0.48:

Causative \Caus"a*tive\, a. [L. causativus pertaining to a
   lawsuit (causa), but in the English sense from E. cause.]
   1. Effective, as a cause or agent; causing.
      [1913 Webster]

            Causative in nature of a number of effects. --Bacon.
      [1913 Webster]

   2. Expressing a cause or reason; causal; as, the ablative is
      a causative case.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Causative \Caus"a*tive\ (k[add]"z[.a]*t[i^]v), n.
   A word which expresses or suggests a cause.
   [1913 Webster]

WordNet (r) 3.0 (2006):

causative
    adj 1: producing an effect; "poverty as a causative factor in
           crime" [ant: noncausal, noncausative]