aequĭnoctĭum, i, n. [aequus-nox],
the time of equal days and nights , the equinox , Cic. Att. 12, 28, 3; Caes. B. G. 4, 36; cf. id. ib. 5, 23, Varr. L. L. 6, § 8 Müll.: autumnale, Liv. 31, 47: vernum, id. 33, 3: aestus duobus aequinoctiis maxime tumentes et autumnali amplius quam verno, etc., Plin. 2, 97, 99, § 215.