Definitions
1.nounThe highest point.
2.nounA tall, sharp and craggy rock or mountain.
3.nounAn all-time high; a point of greatest achievement or success.
4.nounAn 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.
5.verbTo put something on a pinnacle.
6.verbTo build or furnish with a pinnacle or pinnacles.