Rise rapidly (4)
I believe the answer is:
soar
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">rise rapidly</span>' is the definition.<br/ ><span class="explanation-format__explanation">(synonyms)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for soar that I've seen before include "Increase rapidly" , "'Fly, glide (4)'" , "lift" , "Move quickly upward" , "Rise high into the air" .)