Source : Webster's Revised Unabridged Dictionary (1913)

Argosy \Ar"go*sy\, n.; pl. {Argosies}. [Earlier ragusy, fr.
   ragusa meaning orig. a vessel of Ragusa.]
   A large ship, esp. a merchant vessel of the largest size.

         Where your argosies with portly sail . . . Do overpeer
         the petty traffickers.                   --Shak.

Source : WordNet®

argosy
     n : one or more large merchant ships