Source : Webster's Revised Unabridged Dictionary (1913)

Jager \Ja"ger\, n. [G. j["a]ger a hunter, a sportsman. Cf.
   {Yager}.] [Written also {jaeger}.]
   1. (Mil.) A sharpshooter. See {Yager}.

   2. (Zo["o]l.) Any species of gull of the genus
      {Stercorarius}. Three species occur on the Atlantic coast.
      The jagers pursue other species of gulls and force them to
      disgorge their prey. The two middle tail feathers are
      usually decidedly longer than the rest. Called also
      {boatswain}, and {marline-spike bird}. The name is also
      applied to the skua, or Arctic gull ({Megalestris skua}).

Skua \Sku"a\, n. [Icel. sk?fr, sk?mr.] (Zo["o]l.)
   Any jager gull; especially, the {Megalestris skua}; -- called
   also {boatswain}.