Highest mountain (7)
I believe the answer is:
everest
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">highest mountain</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 everest that I've seen before include "Highest Himalayan mountain" , "Highest peak" , "Tee revs up the mountain" , "High peak" , "Himalayan mount" .)