Aspect, element (6)
I believe the answer is:
factor
<span class="explanation-format__ClueExplanation">I believe this clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">aspect</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >'<span class="explanation-format__original">element</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(synonyms)</span><br/ ><br/ ></span>
(Other definitions for factor that I've seen before include "Mathematical quantity" , "Circumstance that contributes toward a result - arithmetically?" , "Circumstance that contributes towards a result" , "for a consideration?" , "Contributing influence; business agent" .)