1. the extreme top or summit

2. the highest level or degree attainable
the highest stage of development

e.g. 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

Synonym: acmeheightelevationpeakpinnaclesummitsuperlativemeridiantop