Source : Webster's Revised Unabridged Dictionary (1913)

Protectionism \Pro*tec"tion*ism\, n. (Polit. Econ.)
   The doctrine or policy of protectionists. See {Protection},
   4.

Source : WordNet®

protectionism
     n : the policy of imposing duties or quotas on imports in order
         to protect home industries from overseas competition