Flat highland (7)
I believe the answer is:
plateau
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">flat highland</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for plateau that I've seen before include "High level land area" , "Large level tract of elevated land" , "hat" , "somewhere flatter?" , "Flat-topped upland" .)