Crash together (7)
I believe the answer is:
collide
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">crash together</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for collide that I've seen before include "Come into conflict" , "Crash together" , "Dash together; clash" , "Smash together" , "Clash; conflict" .)