The Collaborative International Dictionary of English v.0.48:

Regulative \Reg"u*la*tive\ (r?g"?*l?*t?v), a.
   1. Tending to regulate; regulating. --Whewell.
      [1913 Webster]

   2. (Metaph.) Necessarily assumed by the mind as fundamental
      to all other knowledge; furnishing fundamental principles;
      as, the regulative principles, or principles a priori;
      the regulative faculty. --Sir W. Hamilton.
      [1913 Webster]

   Note: These terms are borrowed from Kant, and suggest the
         thought, allowed by Kant, that possibly these
         principles are only true for the human mind, the
         operations and belief of which they regulate.
         [1913 Webster]

WordNet (r) 3.0 (2006):

regulative
    adj 1: restricting according to rules or principles; "a
           regulatory gene" [syn: regulative, regulatory]