Olecranon

The olecranon (/oʊˈlɛkrənɒn/, from Greek olene 'elbow', and kranon 'head'), is a large, thick, curved bony eminence of the ulna, a long bone in the forearm that projects behind the elbow. It forms the most pointed portion of the elbow and is opposite to the cubital fossa or elbow pit. The olecranon serves as a lever for the extensor muscles that straighten the elbow joint.