Source : Webster's Revised Unabridged Dictionary (1913)

Gaucho \Gau"cho\, n.
   A member of an Indian population, somewhat affected by
   Spanish blood, in the archipelagoes off the Chilean coast.

Gaucho \Gau"cho\ (gou"ch[-o]), n., pl. {Gauchos} (-ch[-o]z)
   [Sp.]
   One of the native inhabitants of the pampas, of
   Spanish-American descent. They live mostly by rearing cattle.

Source : WordNet®

gaucho
     n : a cowboy of the South American pampas