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 meeting of heads of governments
"The leaders gathered at the summit to discuss global climate policies."
A peak; the topmost point or surface, as of a mountain.
"After hours of climbing through the snow, we finally reached the summit where the view stretched out to the horizon."
In plain English: A summit is the very top point of a mountain or hill.
"The hikers reached the summit just before sunset."
To reach the summit of a mountain.
"The hikers finally reached the summit after three days of climbing through the snow."
In plain English: To summit means to reach the very top of a mountain.
"The team will summit the mountain before sunset."
Usage: Use this verb to describe physically reaching the highest point of a mountain or, metaphorically, concluding high-level negotiations between leaders. It implies successfully completing an ascent rather than merely being near the top.
Something
"The team worked tirelessly to reach the summit before sunset."
The word "summit" comes from the Late Middle English somet, which was borrowed from Anglo-Norman and French. It originally referred to the top of a mountain or any object before entering English with that same meaning today.