http://www.nmm.ac.uk/server/show/conWebDoc.581

The term was used in the Royal Navy, though I don't know if it still is.
Here is a quote from the link :

Master attendant: managed the ships in harbour and saw to the maintenance of the ships in Ordinary, i.e. when the ship was laid up.

"In Ordinary" is a technical term.

One use is shown here:
Companion to the Standing Orders and guide to the Proceedings of ...
The Lord Chancellor or the Senior Lord of Appeal in Ordinary may recall the ... A Law Lord who has had to retire at 70 as a Lord of Appeal in Ordinary may ...
http://www.parliament.the-stationery-office.c... .

A definition is given by Wikipedia as
Lords of Appeal in Ordinary are Life peers entrusted since the Appellate Jurisdiction Act 1876 with carrying out the judicial functions of the House of Lords

If this is so, maybe the entry in LEO should be capitalized and/or tagged accordingly?!

[...]
PHRASES
in ordinary Brit. (in titles) by
permanent appointment,
especially to the royal
household: painter in ordinary
to Her Majesty.
[New Oxford Dictionary of English]

[...]
18.in ordinary, in regular service: a physician in ordinary to the king.
[Random House Webster's Unabridged]