Lewis & Short

Nī̆nī̆vē, ēs, f., the ancient capital of Assyria, prob. near the mod. Nebbi Yunus, Aug. Civ. Dei, 16, 3; Vulg. Gen. 10, 11; Paul. Nol. Carm. 23, 168; Alcim. 4, 357; also called Ninus or Ninos, v. Ninus.
Hence,

  1. A. Nī̆nĭvītae, ārum, m., the inhabitants of Nineveh, the Ninevites, Prud. Cath. 7, 131; Vulg. Matt. 12, 41.
  2. B. Nĭnĭvī-tĭcus, a, um, adj., Ninevite: puer, Hier. in Isa. 3, 7, 16.