The Collaborative International Dictionary of English v.0.48:

Smuggle \Smug"gle\, v. t. [imp. & p. p. Smuggled; p. pr. & vb.
   n. Smuggling.] [Of Low German or Scand. origin; cf. LG.
   smuggeln, D. smokkelen, G. schmuggeln, Dan. smugle, Sw. smyga
   to introduce or convey secretly, Dan. i smug secretly, D.
   smuigen to eat in secret, AS. sm?gan to creep. See Smock.]
   1. To import or export secretly, contrary to the law; to
      import or export without paying the duties imposed by law;
      as, to smuggle lace.
      [1913 Webster]

   2. Fig.: To convey or introduce clandestinely.
      [1913 Webster]

WordNet (r) 3.0 (2006):

smuggling
    n 1: secretly importing prohibited goods or goods on which duty
         is due

Bouvier's Law Dictionary, Revised 6th Ed (1856):

SMUGGLING. The fraudulent taking into a country, or out of it, merchandise
which is lawfully prohibited. Bac. Ab. h.t.