Lewis & Short

2. Marrŭbĭum or Marrŭvĭum, ii, n.,

  1. I. a city in Latium, the capital of the Marsians, now S. Benedetto, Sil. 8, 507.
    Hence,
  2. II. Marrŭbĭus, a, um, adj., of or belonging to Marrubium, Marrubian: Marrubia gens, Verg. A. 7, 750.
    In plur. subst.: Marrŭvĭi or Marrŭvīni, ōrum, m., the inhabitants of Marrubium, Plin. 3, 12, 17, § 106; cf. Inscr. Orell. 3149.