Lewis & Short

3. ănus, ūs (also uis, Enn. ap. Non. p. 474, 30, or Trag. v. 232 Vahl.; Ter. Heaut. 2, 3, 46; Varr. ap. Non. p. 494, 24; cf. Gell. 4, 16; Prisc. p. 718 P.; v. domus, fructus, victus), f. [cf. old Germ. Ano, Ana, = great-grandfather, great-grandmother; Germ. Ahn, ancestor], an old woman (married or unmarried), a matron, old wife, old maid (sometimes in an honorable sense, but com. as a term of contempt).

  1. I. Lit.: tremulis anus attulit artubus lumen, Enn. ap. Cic. Div. 1, 20, 40 (Ann. v. 36 Vahl.); Plaut. Rud. 2, 3, 75: quid nuntias super anu? id. Cist. 4, 1, 8: ejus anuis causā, Ter. Heaut. 2, 3, 46: prudens, Hor. Epod. 17, 47: pia, Ov. M. 8, 631: huic anui non satis, Plaut. Curc. 1, 2, 16; Vulg. Gen. 18, 13; ib. 1 Tim. 5, 2: quae est anus tam delira, quae ista timeat? Cic. Tusc. 1, 21, 48 et saep.
    Sometimes for a female soothsayer, sibyl, Hor. S. 1, 9, 30; Ov. F. 4, 158.
  2. II. Transf. as adj., old, aged (cf. senex, old; old man, sometimes old woman): anus matronae, Suet. Ner. 11: libertinam quamvis anum, id. Oth. 2.
    Also of animals, or inanimate things of the feminine gender: cerva anus, Ov. A. A. 1, 766: charta, Cat. 68, 46: testa, Mart. 1, 106: terra, Plin. 17, 3, 5, § 35: fici, id. 15, 19, 21, § 82 al.