Source : Webster's Revised Unabridged Dictionary (1913)

Transship \Trans*ship"\, v. t. [Pref. trans- + ship.]
   To transfer from one ship or conveyance to another. [Written
   also {tranship}.]

Source : WordNet®

transship
     v : transfer for further transportation from one ship or
         conveyance to another
     [also: {transshipping}, {transshipped}, {tranship}]