Synonyms for Climax (same or very similar meaning)
WordNet sense 1 (the highest point of anything conceived of as growing or developing or unfolding):
flood tide
WordNet sense 2 (the decisive moment in a novel or play):
culmination
WordNet sense 3 (end, especially to reach a final or climactic stage):
culminate
WordNet sense 4 (the moment of most intense pleasure in sexual intercourse):
coming, sexual climax
From the ODE community, based on WordNet
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