Commencement, inception (6)
I believe the answer is:
outset
<span class="explanation-format__ClueExplanation">This clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">commencement</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(I know that commencement can be written as outset)</span><br/ ><br/ >'<span class="explanation-format__original">inception</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ ></span>
(Other definitions for outset that I've seen before include "Kickoff time?" , "Opening stage" , "Set out in the beginning" , "Beginning, start" , "origin" .)