Dĕl'toid, a.

a. [Fr. deltoïde, from Gr. δελτοειδής, delta-shaped, from δέλτα, the Greek letter, and εἶδος, form. See supra.] Resembling the Greek Δ (delta); triangular.

Deltoid leaf (Bot.), one in the form of a triangle.—Deltoid muscle (Anat.), a muscle in the shoulder which serves to move the arm directly upward.