Culmination, perfection (4)
I believe the answer is:
acme
<span class="explanation-format__ClueExplanation">I believe this clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">culmination</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >'<span class="explanation-format__original">perfection</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(thesaurus)</span><br/ ><br/ ></span>
(Other definitions for acme that I've seen before include "Highest point of excellence or achievement" , "Came awkwardly to the highest point" , "high peak" , "Summit - maximum" , "Height of excellence" .)