Lewis & Short

noxĭōsus, a, um, adj. [noxia] (postAug.).

  1. I. Very hurtful, injurious, or noxious: res, Sen. Ben. 7, 10, 1: noxiosissimo animali (al. noxissimo s. noxiissimo), id. Clem. 1, 26, 3.
  2. II. Full of guilt, vicious, sinful: animi perditi noxiosique, v. l. Sen. Ep. 70, 23: noxiosissimum corpus, Petr. 130, 7.