Main Page | See live article | Alphabetical index Consuetudinary (Med. Lat. consuetudinarius, from consuetudo, custom), customary, a term used especially of law based on custom as opposed to statutory or written law. (See also: Oral law, Custom) As a noun consuetudinary (Lat. consuetudinarius) is the name given to a ritual book containing the forms and ceremonies used in. the services of a particular monastery, cathedral or religious order. This article is from Wikipedia. All text is available under the terms of the GNU Free Documentation License.