Lewis & Short

părĭĕtĭnus, a, um, adj. [paries],

  1. I. of or belonging to walls: parietina forma, the shape of a wall, Tert. Pud. 20: herba, v. parietarius, II.
  2. II. Subst.: părĭĕtĭnae, ārum, f., old fallen-down walls, ruins (class.): villarum, Sisenn. ap. Non. 141, 23: Corinthi, Cic. Tusc. 3, 22, 53; id. Fam. 13, 1, 3: aizoum minus in muris parietinisque nascitur, Plin. 25, 13, 102, § 161; 24, 19, 119, § 183; Vulg. Ezech. 36, 4.
    Trop.: in tantis tenebris et quasi parietinis rei publicae, Cic. Fam. 4, 3, 2.