Source : Webster's Revised Unabridged Dictionary (1913)

Nones \Nones\, n. pl. [L. nonae, so called because it was the
   ninth day before the ides, fr. nonus ninth, from novem nine.
   See {Nine}, {Nones}, 2, {Noon} .]
   1. (Roman Cal.) The fifth day of the months January,
      February, April, June, August, September, November, and
      December, and the seventh day of March, May, July, and
      October. The nones were nine days before the ides,
      reckoning inclusively, according to the Roman method.

   2. [F. none, fr. L. See {Noon}.] The canonical office, being
      a part of the Breviary, recited at noon (formerly at the
      ninth hour, 3 P. M.) in the Roman Catholic Church.

   3. The hour of dinner; the noonday meal. [Obs.]

            At my supper and sometimes at nones.  --P. Plowman.

Source : WordNet®

nones
     n : the fifth of the seven canonical hours; about 3 p.m.