Cause to begin (8)
I believe the answer is:
initiate
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">cause to begin</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 initiate that I've seen before include "Originate" , "Start - trigger" , "Cause to begin or admit to membership" , "Cause (action) to begin" , "starter" .)