Source : Webster's Revised Unabridged Dictionary (1913)

Nylghau \Nyl"ghau\, Nylgau \Nyl"gau\, n. [Hind. & Per.
   n[=i]lg[=a]w, prop., a blue cow; Per. n[=i]l blue + g[=a]w
   cow. See {Lilac}, and {Cow} the animal.] (Zo["o]l.)
   A large Asiatic antelope ({Boselaphus, or Portax,
   tragocamelus}), found in Northern India. It has short horns,
   a black mane, and a bunch of long hair on the throat. The
   general color is grayish brown. [Written also {neelghau},
   {nilgau}, and {nylghaie}.]