Siren, in Greek mythology, one of three sea nymphs, usually represented with the head of a woman and the body of a bird. Daughters of Phorcus or of Achelous, the Sirens inhabited an island surrounded by dangerous rocks. They sang so enchantingly that all who heard were drawn near and shipwrecked. Jason and the Argonauts were saved from them by the music of Orpheus, whose songs were lovelier. Odysseus escaped them by having himself tied securely to a mast and by stopping the ears of his men.