Source : Webster's Revised Unabridged Dictionary (1913)

Darter \Dart"er\, n.
   1. One who darts, or who throw darts; that which darts.

   2. (Zo["o]l.) The snakebird, a water bird of the genus
      {Plotus}; -- so called because it darts out its long,
      snakelike neck at its prey. See {Snakebird}.

   3. (Zo["o]l.) A small fresh-water etheostomoid fish. The
      group includes numerous genera and species, all of them
      American. See {Etheostomoid}.

Source : WordNet®

darter
     n 1: fish-eating bird of warm inland waters having a long
          flexible neck and slender sharp-pointed bill [syn: {snakebird},
           {anhinga}]
     2: a person or other animal that moves abruptly and rapidly;
        "squirrels are darters"