Source : Webster's Revised Unabridged Dictionary (1913)

Water monitor \Wa"ter mon"i*tor\ (Zo["o]l.)
   A very large lizard ({Varanaus salvator}) native of India. It
   frequents the borders of streams and swims actively. It
   becomes five or six feet long. Called also {two-banded
   monitor}, and {kabaragoya}. The name is also applied to other
   aquatic monitors.