culmination

Short definition from Wiktionary

Noun

1. 1
   The attainment of the highest point of altitude reached by a heavenly body; passage across the meridian; transit.
2. 2
   An endpoint arrived at after some series of actions or events, or some period, usually after the series or period has ended. The sum of something.
3. 3
   An attainment or arrival at the highest pitch of glory, power, etc.
4. 4
   A ceremony marking the completion of studies at an elementary school, middle school or junior high school.