Lewis & Short

sexāgēnārĭus, a, um, adj. [sexageni].

  1. I. In gen., of or containing sixty: fistula, a pipe sixty quarter-digits (quadrantes) in diameter, Front. Aquaed. 54: PROCVRATIO, i. e. yielding sixty thousand sesterces, Inscr. Murat. 514, 1.
  2. II. In partic., sixty years old, sexagenary; and subst., a man of sixty, a sexagenarian: Cicero objurgantibus, quod sexagenarius Publiliam virginem duxisset, etc., Quint. 6, 3, 75; Suet. Claud. 23: (Hadrianus) obiit major sexagenario, Eutr. 8, 3, 8.
    Men sixty years of age were no longer admitted to vote in the saepta, and, if they attempted to enter, were thrust back from the bridge leading to them; whence arose the proverb, Sexagenarios de ponte, Varr. ap. Non. 523, 21 sq.; Fest. p. 334 Müll.; cf.: depontani. (Many Romans, at an early period, erroneously referred this expression to a religious usage, and even to original human sacrifices; v. Fest. 1. 1., and Ov. F. 5, 621 sq.)
    In a sarcastic equivoque, of actually flinging a man into the Tiber, Cic. Rosc. Am. 35, 100.