Lewis & Short

spectābĭlis, e, adj. [specto].

  1. I. In gen., that may be seen, visible: corpus caeli, Cic. Univ. 8 (al. aspectabile); so, corpus, Ov. Tr. 3, 8, 35: purus ab arboribus, spectabilis undique campus, i. e. open, id. M. 3, 709.
  2. II. Pregn., that is worth seeing, notable, admirable, remarkable (only poet. and in post-Aug. prose): Niobe Vestibus intexto Phrygiis spectabilis auro, Ov. M. 6, 166: quod sit roseo spectabilis ore, id. ib. 7, 705: heros, id. ib. 7, 496: mons topiario naturae opere, Plin. 4, 8, 15, § 29: flumen portu, id. 5, 1, 1, § 13: texenda spectabili subtilitate, id. 16, 37, 68, § 174: pulchra et spectabilis victoria, Tac. Agr. 34 fin.: mater spectabile tela duxit opus, Val. Fl. 1, 429.
    1. B. Under the emperors: Spectabilis, a title of high officers: apud virum Spectabilem proconsulem, Cod. Just. 2, 7, 11 fin.: judices, ib. 7, 62, 32: praefectus vigilum, Dig. 1, 15, 3.