olecranon /ōlek″rənon/ [Gk, olekranon, tip of the elbow] , a proximal projection of the ulna that forms the tip of the elbow and fits into the olecranon fossa of the humerus when the forearm is extended. The anterior surface of the olecranon forms part of the trochlear notch that articulates with the trochlea of the humerus. Also called olecranon process.
