Lewis & Short

cortex, ĭcis, m. and rar. f. (cf. Quint. 1, 5, 35) [Sanscr. kart, to cut, split; Gr. κείρω; cf. culter], the bark, rind, shell, hull.

  1. I. Prop., of plants: obducuntur libro aut cortice trunci, Cic. N. D. 2, 47, 120.
    1. A. In gen.
          1. (α) Masc., Varr. ap. Non. p. 199, 26; Verg. G. 2, 74; id. A. 7, 742; Ov. M. 1, 554; id. F. 2, 649; Plin. 2, 103, 106, § 226 al.; cf. infra.
          2. (β) Fem., Lucr. 4, 48; Verg. E. 6, 63; Ov. M. 10, 512; 14, 630; Mart. 14, 209; Scrib. Comp. 60.
    2. B. In partic., the bark of the cork-tree, cork, used for stoppers, Cato, R. R. 120; (masc.) Hor. C. 3, 8, 10; in learning to swim; hence prov.: nare sine cortice, to need no more assistance, id. S. 1, 4, 120
      From its lightness is borrowed the phrase: tu levior cortice, Hor. C. 3, 9, 22; cf.: ut summā cortex levis innatet undā, Ov. Tr. 3, 4, 11.
  2. II. Transf., of other shells than those of vegetables: ovi, Vitr. 8, 3.
    1. B. Trop., the outward part, covering, i. e. the body: anima corporeum corticem reliquit, Varr. ap. Non. p. 199, 29.