1. (noun)acme, height, elevation, peak, pinnacle, summit, superlative, meridian, tiptop, top the highest level or degree attainable; the highest stage of development "his landscapes were deemed the acme of beauty"; "the artist's gifts are at their acme"; "at the height of her career"; "the peak of perfection"; "summer was at its peak"; "...catapulted Einstein to the pinnacle of fame"; "the summit of his ambition"; "so many highest superlatives achieved by man"; "at the top of his profession"
2. (noun)vertex, peak, apex, acme the highest point (of something)
"at the peak of the pyramid"