1 [usuallysing.] ~ of sth the most important or successful part of sth:
the pinnacle of her career * He spent more than twenty years at the pinnacle of his profession. * Formula One is the pinnacle of motor racing.
2 a small pointed stone ornament built on the roof of a building:
We could just make out the pinnacles of the cathedral in the distance.
3 a high pointed piece of rock, especially at the top of a mountain
