[ 'dɛltɔɪd ]
■ adjective technical
1》 triangular.
2》 denoting a thick triangular muscle covering the shoulder joint and used for raising the arm away from the body.
■ noun a ~ muscle, or one of the three parts of a ~ muscle.
Origin
C18: from Fr. deltoïde , or via mod. L. from Gk deltoeidēs .