What is the meaning of Pinnacle?

The highest point.

A tall, sharp and craggy rock or mountain.

An all-time high; a point of greatest achievement or success.

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.

To place on a pinnacle.

To build or furnish with a pinnacle or pinnacles.

Source: wiktionary.org