a Roman jurisconsult, of uncertain date. He probably lived under Trajan, and, according to the conjecture of Grotius, is perhaps the same person with the orator Arrianus, who corresponded with the younger Pliny. (Plin. Ep. 1.2, 2.11, 12, 4.8, 8.21.) He may also possibly be identical with the Arrianus Severus, praefectus aerarii, whose opinion concerning a constitution Divi Trajani is cited by Aburnus Valens. (Dig. 49. tit. 14. s. 42.) He wrote a treatise de Interdietis, of which the second book is quoted in the Digest in an extract from Ulpian. (Dig. 5. tit. 3. s. 11.) In that extract, Proculus, who lived under Tiberius, is mentioned in such a manner, that he might be supposed to have written after Arrianus. There is no direct extract from Arrianus in the Digest, though he is several times mentioned. (Majansius, vol. ii. p. 219; Zimmern, Röm. Rechts-Geschichte, 1.90.)