In ordinary

In ordinary as a phrase has two technical meanings recorded by the Oxford English Dictionary:

1. In relation particularly to the staff of the British royal household, and more generally to those employed by the Crown, it is used as a suffix showing that the appointment is to the regular staff, for example a chaplain in ordinary, or a physician-in-ordinary, being a cleric or doctor in regular attendance. The usage goes back to the seventeenth century. See for example: Category:Physicians-in-Ordinary; Principal Painter in Ordinary; Lords of Appeal in Ordinary.
2. In naval matters, vessels in ordinary (from the eighteenth century) are those out of service for repair or maintenance, a meaning coming over time to cover a reserve fleet or "mothballed" ships.