Spanish mountain range (6)
I believe the answer is:
sierra
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">spanish mountain range</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for sierra that I've seen before include "One range" , "- - Leone" , "A Spanish mountain chain (6)" , "------ Nevada, mountains of Spain and California" , "letter read out on the radio" .)