pinnacle

Short definition from Wiktionary

Noun

1. 1
   The highest point.
2. 2
   A tall, sharp and craggy rock or mountain.
3. 3
   An all-time high; a point of greatest achievement or success.
4. 4
   An upright member, generally ending in a small spire, used to finish a buttress, to constitute a part in a proportion, as where pinnacles flank a gable or spire.

Verb

1. 1
   To place on a pinnacle.
2. 2
   To build or furnish with a pinnacle or pinnacles.