Flatten under pressure (8)
I believe the answer is:
compress
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">flatten under pressure</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for compress that I've seen before include "Make more compact" , "Squeeze together or squash" , "Reduce by squeezing" , "Squeeze into less space" , "Crush" .)