(architecture) a slender upright spire at the top of a buttress of tower
"The ancient cathedral features a delicate pinnacle crowning the western tower's main buttress."
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"
a lofty peak
"The climbers reached the pinnacle of the mountain just as the sun began to set."
The highest point.
"The mountain's summit marked the geographical pinnacle where the air grew thin and cold."
To place on a pinnacle.
"The statue was placed on a pinnacle overlooking the city square."
The word "pinnacle" comes from the Old French term pinacle, which was borrowed from Late Latin pinnaculum. This Latin root originally meant a peak or spire and is related to the Latin word for a feather or wing, pinna.