the highest point or part, as of a hill, a line of travel, or any object; top; apex.

the highest point of attainment or aspiration

the summit of one's ambition.

the highest state or degree.

the highest level of diplomatic or other governmental officials

a meeting at the summit.

summit meeting.

of or pertaining to a summit meeting

summit talks.

to take part in a summit meeting.

to reach a summit

summited after a 14-hour climb.

to reach the summit of.

noun

base , bottom , nadir

noun

acme , apex , apogee , capstone , climax , crest , crown , culmination , head , height , max , meridian , most , peak , pinnacle , roof , vertex , zenith , cap , top , arete , consummation , mountain , spire , tip