Culminate (6)
I believe the answer is:
climax
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">culminate</span>' is the definition.<br/ ><span class="explanation-format__explanation">(synonyms)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for climax that I've seen before include "exciting finale" , "Turning point or culmination" , "Most intense point" , "Most exciting point" , "Turning point, moment of greatest intensity" .)