pin·na·cle / ˈpinəkəl/ • n. a high, pointed piece of rock. ∎ a small pointed turret built as an ornament on a roof. ∎ the most successful point; the culmination: he had reached the pinnacle of his career.• v. [tr.] poetic/lit. set on or as if on a pinnacle: a rustic cross was pinnacled upon the makeshift altar. ∎ form the culminating point or example of.DERIVATIVES: pin·na·cled adj.