The Collaborative International Dictionary of English v.0.48:

Culmination \Cul"mi*na"tion\ (k[u^]l`m?-n?"sh?n), n. [Cf.
   F.culmination]
   1. The attainment of the highest point of altitude reached by
      a heavenly body; passage across the meridian; transit.
      [1913 Webster]

   2. Attainment or arrival at the highest pitch of glory,
      power, etc.
      [1913 Webster]

WordNet (r) 3.0 (2006):

culmination
    n 1: a final climactic stage; "their achievements stand as a
         culmination of centuries of development" [syn: apogee,
         culmination]
    2: (astronomy) a heavenly body's highest celestial point above
       an observer's horizon
    3: the decisive moment in a novel or play; "the deathbed scene
       is the climax of the play" [syn: climax, culmination]
    4: a concluding action [syn: completion, culmination,
       closing, windup, mop up]

Moby Thesaurus II by Grady Ward, 1.0:

129 Moby Thesaurus words for "culmination":
   Z, accomplishment, acme, acme of perfection, apex, apodosis,
   apogee, bitter end, brow, cap, catastrophe, ceasing, cessation,
   climax, close, closure, cloud nine, coda, completing, completion,
   conclusion, consummation, crack of doom, crest, crown, culmen,
   curtain, curtains, death, decease, denouement, destination,
   destiny, doom, edge, effect, end, end point, end result, ending,
   envoi, epilogue, eschatology, expiration, extreme limit, extremity,
   fate, final result, final solution, final twitch, final words,
   finale, finality, finis, finish, finishing, fulfillment,
   full development, goal, heaven, heavens, height, high noon,
   highest pitch, highest point, izzard, last, last act, last breath,
   last gasp, last things, last trumpet, last word, last words,
   latter end, limit, maturation, maturity, maximum, meridian,
   mountaintop, ne plus ultra, no place higher, noon, omega, payoff,
   peak, perfection, period, peroration, pink, pink of perfection,
   pinnacle, pitch, point, pole, quietus, realization, resolution,
   resting place, ridge, ripeness, rounding off, rounding out,
   seventh heaven, sky, spire, stoppage, stopping place, summit,
   swan song, term, terminal, termination, terminus, tip, tip-top,
   top, topping off, topping-off, ultimate, upmost, upper extremity,
   uppermost, utmost, vertex, very top, windup, zenith