Implode (8)
I believe the answer is:
collapse
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">implode</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 collapse that I've seen before include "Fall down or lose strength suddenly" , "Break down - fall" , "Go to ruin" , "Fall down suddenly like escallop" , "Give way or cave in" .)