The Collaborative International Dictionary of English v.0.48:

Sargo \Sar"go\, n. [Sp. sargo, L. sargus a kind of fish.]
   (Zool.)
   Any one of several species of sparoid fishes belonging to
   Sargus, Pomadasys, and related genera; -- called also
   sar, and saragu.
   [1913 Webster]