Cowboy of the South American pampas (6)
I believe the answer is:
gaucho
'cowboy of the south american pampas' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for gaucho that I've seen before include "Plain-living person" , "plainsman" , "A cough (anag)" , "Cowboy of Argentine's plains" , "Cowboy of the South American pampas" .)