From Longman Dictionary of Contemporary Englishpinnaclepin‧na‧cle /ˈpɪnəkəl/ noun 1 [singular]SUCCESSFUL the most successful, powerful, exciting etc part of something the pinnacle of academic achievementpinnacle of She had reached the pinnacle of her political career.at the pinnacle of something The bank was then at the pinnacle of England’s financial system.2 [countable] literaryDN a high mountain top3 [countable]TBB a pointed stone decoration, like a small tower, on a building such as a church or castle
Examples from the Corpus
pinnacle• At last we could see Ambadji on a pinnacle ahead of us.• The end of the war in 1945 was his pinnacle.• Troops may be moved on to a castle wall, rocky pinnacle or other elevation including a Spiral Stair.• Then, just before dusk a single figure was spotted again moving out of sight on the small col below the second pinnacle.• To deplore children being crippled by land mines is not really at the pinnacle of human courage, is it?• During the seven years of their previous patronage by Next, the brothers have reached the pinnacle of the sport.• The towers spring from sprawling castle-like buildings that were once hotels representing the pinnacle of elegance.pinnacle of• By 1965, Fellini had reached the pinnacle of his commercial success.Origin pinnacle (1200-1300) Old French pinacle, from Late Latin pinnaculum, from Latin pinna “wing, wall around the top of a castle” 