Gain altitude (6)
I believe the answer is:
ascend
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">gain altitude</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 ascend that I've seen before include "Come up" , "Dances (anag.)" , "Gain altitude" , "Move upwards" , "rise in status" .)