Crumble under pressure (4)
I believe the answer is:
wilt
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">crumble under pressure</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 wilt that I've seen before include "Droop in the heat" , "Ave --; black --" , "fade" , "Decline" , "Lose strength and become limp" .)