1. In the ancient Roman calendar, the ninth day (inclusively) before the ides of a month, falling on the seventh day of March, May, July, or October and the fifth day of the other months.
a. The fifth of the seven canonical hours. No longer in liturgical use.
b. The time of day appointed for this service, usually the ninth hour after sunrise.
[Middle English, from Old French, from Latin nōnae, feminine pl. of nōnus, ninth; see new in the Appendix of Indo-European roots.]
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