The Collaborative International Dictionary of English v.0.48:

Jaculator \Jac"u*la`tor\, [L.]
   1. One who throws or casts. [R.]
      [1913 Webster]

   2. (Zool.) The archer fish (Toxotes jaculator).
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The Collaborative International Dictionary of English v.0.48:

Archer fish \Arch"er fish`\ (Zool.)
   A small fish (Toxotes jaculator), of the East Indies; -- so
   called from its ejecting drops of water from its mouth at its
   prey. The name is also applied to Ch[ae]todon rostratus.
   [1913 Webster]