Yes, OLECRANON is a Scrabble word!

Letter values in Scrabble US: O 1, L 1, E 1, C 3, R 1, A 1, N 1, O 1, N 1.

Is it a valid word?

OLECRANON is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

process of the ulna that forms the outer bump of the elbow and fits into the fossa of the humerus when the arm is extended

Also: olecranon process.