[T]he Book of St. Albans, in the sections on blasonry, lays great stress on the nines in which all perfect things (orders of angels, virtues, articles of chivalry, differences of coat armour, etc.) occur. [Weekley]No one seems to consider that it might be a corruption and misdivision of to then anes, literally "for the one (purpose or occasion)," a similar construction to the one that yielded nonce (q.v.).