Lewis & Short

cānus, a, um, adj. [Sanscr. Kas-, to shine; cf. cascus], white, hoary (mostly poet.).

  1. I. Lit.: fluctus, Lucr. 2, 767; Cic. Arat. 71; hence aqua, foamy, frothy, Ov. H. 2, 16: nix, white, Lucr. 3, 21; Hor. S. 2, 5, 41: gelu, Verg. G. 3, 442: montes, id. ib. 1, 43: pruina, hoar-frost, Hor. C. 1, 4, 4: grandine canus Athos, Ov. Ib. 200: salicta, id. M. 5, 590: segetes, id. ib. 10, 655: aristae, id. ib. 6, 456: lupus, id. ib. 6, 527; 7, 550: favilla, id. ib. 8, 524: color equi, Pall. Mart. 14, 4: arborum villi, Plin. 12, 23, 50, § 108: situs, id. 12, 25, 55, § 125.
    1. B. Esp. freq. of the gray hair of the aged: cano capite atque albā barbā, Plaut. Bacch. 5, 1, 15; id. As. 5, 2, 84; Cat. 68, 124; Tib. 1, 1, 72; Ov. F. 5, 57: capilli, Hor. C. 2, 11, 15; Ov. M. 1, 266; 2, 30; 4, 474; Phaedr. 2, 2, 10: crinis, Cat. 64, 350; Ov. M. 13, 427: barba, Mart. 4, 36 al.
      Hence, subst. in plur.: cāni, ōrum, m. (sc. capilli), gray hairs: non cani, non rugae repente auctoritatem arripere possunt, Cic. Sen. 18, 62; Ov. M. 3, 275; in Aug. and post-Aug. poets (esp. freq. in Ovid) with adjj.: falsi, Ov. M. 6, 26: honorati, id. ib. 8, 9: positi, id. ib. 14, 655: rari, id. ib. 8, 567: sui, id. ib. 10, 391: miseri, Pers. 5, 65: venerandi. Sen. Herc. Fur. 1249.
      Hence,
  2. II. Transf., of age and of aged persons. old, aged: senectus, hoary, Cat. 108, 1: anilitas, id. 61, 162: amator, Tib. 1, 8, 29: cana veritas, venerable, Varr. ap. Non. p. 243, 1: Fides, Verg. A. 1, 292: Vesta, id. ib. 5, 744.