O / Orpheus
noun

Orpheus

gen. Orphei · gender masculine · decl. 2nd
(), (Gr. dat. Orphei, Verg. E. 4, 57; Gr. acc. Orphĕă, Verg. E. 6, 30; Ov. P. 3, 3, 41:
the famous mythic singer of Thrace; son of Œagrus and Calliope; and husband of Eurydice; after her death he led her back from the Lower World
Orphēā, id. M. 10, 3; voc. Orpheu, Verg. G. 4, 494; Ov. M. 11, 44), m., = Ὀρφεύς, the famous mythic singer of Thrace, son of Œagrus and Calliope, and husband of Eurydice; after her death he led her back from the Lower World, but lost her on turning to look at her, breaking his promise to Pluto. He was one of the Argonauts, Hor. C. 1, 12, 8; Ov. M. 10, 3 sq.; 11, 5 sq.; Hyg. Fab. 164; 251; Verg. E. 4, 55; Cic. N. D. 1, 38, 107 et saep.—Hence,
belonging to Orpheus; Orphean poetic
Or-phēus, a, um, adj., = Ὀρφεῖος, of or belonging to Orpheus, Orphean (poet.): vox, Ov. M. 10, 3: lyra, Prop. 1, 3, 42.—
belonging to Orpheus; Orphic
Or-phĭcus, a, um, adj., = Ὀρφικός, of or belonging to Orpheus, Orphic (class.): carmen, Cic. N. D. 1, 38, 107: sacra Orphica, id. 3, 23, 58: versus, Macr. S. 1, 18, 17.—
Orphic; the Orphics; the followers of Orpheus
Orphăĭcus, a, um, adj., = Ὀρφαικός, Orphic.—In plur. subst.: Orphăĭci, ōrum, m., the Orphics, the followers of Orpheus, Macr. Somn. Scip. 1, 12.