Twelve o'clock in the day; midday. In Old English, nōn means ‘the ninth hour from sunrise’, i.e. approximately 3 p.m., from Latin nona (hora) ‘ninth hour’.
It was traditionally believed that the change in the time denoted by noon, from about 3 o'clock to about 12 o'clock, probably resulted from anticipation of the ecclesiastical office or of a meal hour; this view was based on the belief that the canonical hours were counted starting at 6 o'clock, and that in the Benedictine order nones would ordinarily be held at about 3 o'clock. Recent research, however, suggests that in the Benedictine order in Italy nones would have been held closer to 12 o'clock, and it is possible that this became the usual time for nones in several orders.