Gaucho's plain (5)
I believe the answer is:
llano
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">gaucho's plain</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for llano that I've seen before include "Treeless grassy plain in South America" , "Treeless area" , "(South American) grassy plain" , "Grassy plain in South?America" , "Flat area" .)