(Θεόδοκος), the name given by Pococke (in his Latin Version of Abú-l-Faraj, Hist. Dynast. p. 128), and Wüstenfeld (Gesch. der Arab. Aerzte, p. 9) to a Greek physician in the service of Hajáj Ibn Yúsuf, the general of the chalif 'Abdu-l-Malek Ibn Merwán, in the seventh century after Christ. He is called in Arabic Tíádúk (though with some slight variations in different MSS.), which Reiske (Opusc. Med. ex Monim. Arab. p. 46) renders Theotychus, but Theodocus is probably nearer the truth. He is said to have had numerous eminent pupils; and is probably the person called Tiaducus in the Latin Version of Rhazes (Cont. 3.2, p. 53 ed. 1506,) and Tiaduk in Sontheimer's German translation of Ibn Baitár (vol. i. pp. 14, 137, &c.). There is rather a long life of Theodocus in Ibn Abí Osaibi'ah (7.5, Arab. MS. in the Bodleian Library), which is chiefly filled with anecdotes of his sayings.