Definition of "yager"

There are fourscore of them; and but that each carries a yager rifle in his hand, a knife in his belt, and a Colt's pistol on his thigh, you could not discover the slightest point of resemblance between any two of them.

1857, Mayne Reid, The War Trail‎

Many present identify it as the yager usually carried by Clancy.

1874, Mayne Reid, The Death Shot‎

We were each armed with a Mississippi yager and two Colt's revolvers.

1879, William F. Cody, The Life of Hon. William F. Cody‎

Most of the officers were dressed in […] a bluish-grey frock-coat of a colour similar to Austrian yagers.

1863, Arthur J. L. (Lieut.-Col.) Fremantle, Three Months in the Southern States, April-June 1863‎

A battalion of yagers, the pride of the Austrian army, charged up the fatal hill and succeeded in taking it, after which the rattle of musketry beyond announced that the fight was being continued on the farther side.

1901, Maurus Jokai, Manasseh‎

Three days after this affair, Colonel Richard Butler, with a detachment of infantry, assisted by Major Lee with a part of his cavalry, fell in with a small party of chasseurs and yagers under Captain Donop, which he instantly charged, and, without the loss of a man, killed ten on the spot, and took the officer commanding the chasseur, and eighteen of the yagers, prisoners.

1926, John Marshall, The Life of George Washington, Vol. 3 (of 5)‎