Lewis & Short

Īsis, is, and ĭdis. f., = Ἶσις,

  1. I. the Egyptian goddess Isis, Cic. N. D. 3, 19, 47; Ov. M. 9, 772; Tac. G. 9; Luc. 9, 158.
    1. B. Hence,
      1. 1. Isidis crinis, an unknown plant, Juba ap. Plin. 13, 25, 52, § 142.
      2. 2. Isidis sidus, the planet Venus, Plin. 2, 8, 6, § 37.
  2. II. Deriv. Īsĭăcus, a, um, adj., = Ἰσιακός, of or belonging to Isis: conjectores, Enn. ap. Cic. Div. 1, 58, 132: focus, Ov. P. 1, 1, 52: Isiacae sacraria lenae, Juv. 6, 488.
    Subst.: Īsĭă-cus, i, m., a priest of Isis, Suet. Dom. 1; Val. Max. 7, 3, 8; Plin. 27, 7, 29, § 53 al.