Lewis & Short

1. auctumnus (correctly aut-), i, m. (autumnum, i, n., Varr.ap.Non.p.71, 20). [This word was anciently referred to augeo, as the season of increase, as by Paul. ex Fest. p. 23, 11 Müll.; so Curtius. But Corssen and others, in view of its correct form, autumnus, refer it to the Sanscr. av, to do good to, to satisfy one’s self; cf. the Gr. ἐνηνής (i.e. ἐνηϝής), good, kindly, and 2.aveo, to be well.] The season of abundance, the autumn.

  1. I. Lit. (from the 22d of September to the 22d of December; acc. to the designation of the ancients, from the entering of the sun into Libra until the setting of the Pleiades, comprising 91 days, Varr. R. R. 1, 28): quae temporis quasi naturam notant, hiems, ver, aestas, autumnus, Cic. Part. Or. 11: Vites autumno fundi suadente videmus, Lucr. 1, 175: Inde autumnus adit, id. 5, 743: pomifer, Hor. C. 4, 7, 11: varius purpureo colore, id. ib. 2, 5, 11: sordidus calcatis uvis, Ov. M. 2, 29: letifer, sickly (on account of the diseases that prevail in autumn), Juv. 4, 56: sub autumno, Ov. A. A. 2, 315: autumno adulto, about the middle of autumn, Tac. A. 11, 31: vergente, drawing to a close, id. ib. 11, 4: flexus autumni, id. H. 5, 23 al.
    In plur.: Frustra per autumnos nocentem Corporibus metuemus Austrum, Hor. C. 2, 14, 15; Ov. M. 1, 117; 3, 327.
  2. * II. Meton., the produce of the autumn, the harvest: et multa fragrat testa senibus autumnis, i. e. vino vetere, Mart. 3, 58, 7.