Educational Content: This article is for informational purposes only and does not constitute medical advice. Always consult a healthcare provider for diagnosis and treatment.

Definition of Deltoid

Medically reviewed by Min Clinic Staff | Updated: January 2026

Deltoid: The muscle, roughly triangular in shape, that stretches from the collarbone (clavicle) over the shoulder to the upper bone of the arm (humerus). It contracts to move the arm up from the side.