Lewis & Short

substantĭālis, e, adj. [substantia].

  1. I. Lit., of or belonging to the essence or substance, essential, substantial (post-class.): differentia, Tert. Res. Carn. 45 fin.
  2. II. Transf., substantial, substantive: potestates, i. e. spirits, Amm. 21, 1, 8.
    Adv.: sub-stantĭālĭter, essentially, substantially, Tert. adv. Valent. 7, 4; id. adv. Marc. 35 fin.