Definition of "Summit" :

noun: a meeting of heads of governments

noun: the top or extreme point of something (usually a mountain or hill)

"The region is a few molecules wide at the summit."

noun: the highest level or degree attainable; the highest stage of development

"The summit of his ambition."

verb: reach the summit (of a mountain)

"Many mountaineers go up Mt. Everest but not all summit."