What is the meaning of pinnacle?

noun

• Architecture) a slender upright spire at the top of a buttress of tower. (
• The highest level or degree attainable; the highest stage of development.
  • usage: "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"
  • synonyms: acme, height, elevation, peak, summit, superlative, meridian, tiptop, top
• A lofty peak.

verb

• Surmount with a pinnacle.
  • usage: "pinnacle a pediment"
• Raise on or as if on a pinnacle.
  • usage: "He did not want to be pinnacled"