Make one (5)
I believe the answer is:
unify
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">make one</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 unify that I've seen before include "Consolidate" , "Merge" , "Make as one" , "Combine" , "Get together" .)