[del.toid] n [NL deltoides, fr. Gk deltoeides shaped like a delta, fr. delta] (ca. 1681): a large triangular muscle that covers the shoulder joint and serves to raise the arm laterally
[2]deltoid adj (ca. 1753) 1: having a triangular shape "a ~ leaf"--see leaf illustration
2: relating to, associated with, or supplying the deltoid