1. A large triangular muscle covering the shoulder joint and serving to abduct and flex and extend and rotate the arm
   "Weightlifters often focus on developing their deltoids for a broader shoulder appearance";
   - deltoid muscle, musculus deltoideus, delt [informal]

1. Triangular or suggesting a capital delta, with a point at the apex
   "The deltoid muscle in the shoulder has a triangular shape"

Derived forms: deltoids

See also: simple, unsubdivided

Type of: skeletal muscle, striated muscle

Part of: rotator cuff

Encyclopedia: Deltoid