Source : Webster's Revised Unabridged Dictionary (1913)

Restrictive \Re*strict"ive\, a. [Cf. F. restrictif.]
   1. Serving or tending to restrict; limiting; as, a
      restrictive particle; restrictive laws of trade.

   2. Astringent or styptic in effect. [Obs.] --Wiseman.
      --{Re*strict"ive*ly}, adv. -- {Re*strict"ive*ness}, n.

Source : WordNet®

restrictiveness
     n : modification that makes the meaning more specific (`red hat'
         has a more specific meaning than `hat')