The Collaborative International Dictionary of English v.0.48:

Protective \Pro*tect"ive\, a. [Cf. F. protectif.]
   Affording protection; sheltering; defensive. " The favor of a
   protective Providence." --Feltham.
   [1913 Webster]

   Protective coloring (Zool.), coloring which serves for the
      concealment and preservation of a living organism. Cf.
      Mimicry. --Wallace.

   Protective tariff (Polit. Econ.), a tariff designed to
      secure protection (see Protection, 4.), as distinguished
      from a tariff designed to raise revenue. See Tariff, and
      Protection, 4.
      [1913 Webster]

WordNet (r) 3.0 (2006):

protective tariff
    n 1: a tariff imposed to protect domestic firms from import
         competition