1. In the ancient Roman calendar, the ninth day before the Ides of a month (counting inclusively), falling on the 5th of most months and the 7th of March, May, July, and October.
Usage: historical; usually used in plural form; Latin term used in English historical and classical contexts

Examples

• The Nonas of March was an important date in the Roman calendar.
• Scholars studying Roman history often encounter references to the Nonas in ancient texts.
• The meeting was scheduled for the Nonas of June according to the old Roman system.
• In most months, the Nonas fell on the fifth day.
• The Nonas represented a fixed point for organizing the Roman month.