What is the meaning of culmination?

noun

• A final climactic stage.
  • usage: "their achievements stand as a culmination of centuries of development"
  • synonyms: apogee
• Astronomy) a heavenly body's highest celestial point above an observer's horizon. (
• The decisive moment in a novel or play.
  • usage: "the deathbed scene is the climax of the play"
  • synonyms: climax
• A concluding action.
  • synonyms: completion, closing, windup, mop up