1. In ecclesiastical affairs, a law, or rule of doctrine or discipline, enacted by a council and confirmed by the sovereign; a decision of matters in religion, or a regulation of policy or discipline, by a general or provincial council.
2. A law or rule in general.
3. The genuine books of the Holy Scriptures, called the sacred cannon, or general rule of moral and religious duty, given by inspiration.
4. A dignitary of the church; a person who possesses a prebend or revenue allotted for the performance of divine service in a cathedral or collegiate church.
A cardinal canon is one attached to a church, incardinatus, as a priest to a parish.
Domicellary canons, are young canons, not in orders, having no right in any particular chapters.
Expectative canons, having no revenue or prebend, but having the title and dignities of canons, a voice in the chapter and a place in the choir, till a prebend should fall.
Foreign canons, such as did not officiate in their canonries; opposed to mansionary or residentiary canons.
Lay, secular or honorary canons, laymen admitted out of honor or respect, into some chapter of canons.
Regular canons, who live in monasteries or in community, and who, to the practice of their rules, have added the profession of vows.
Tertiary canons, who have only the third part of the revenue of the canonicate.
5. In monasteries, a book containing the rules of the order.
6. A catalogue of saints acknowledged and canonized in the Romish Church.
7. The secret words of the mass from the preface to the Pater, in the middle of which the priest consecrates the host. The people are to rehearse this part of the service, on their knees, and in a voice lower than can be heard.
8. In ancient music, a rule or method for determining the intervals of notes, invented by Ptolemy.
9. In modern music, a kind of perpetual fugue, in which the different parts, beginning one after another, repeat incessantly the same air.
10. In geometry and algebra, a general rule for the solution of cases of a like nature with the present inquiry. Every last step of an equation is a canon
11. In pharmacy, a rule for compounding medicines.
12. In surgery, an instrument used in sewing up wounds.
Canon-law, is a collection of ecclesiastical laws, serving as the rule of church government.