Synonyms for Summit (same or very similar meaning)
WordNet sense 1 (the highest level or degree attainable; the highest stage of development):
acme, elevation, height, meridian, peak, pinnacle, superlative, tiptop, topWordNet sense 2 (the top point of a mountain or hill):
crest, crown, tipWordNet sense 3 (a meeting of heads of governments):
summit meetingFrom the ODE community, based on WordNetadd/edit