See canon in Webster's New World College Dictionary
noun
a law or body of laws of a church
Rare any law or decree
an established or basic rule or principle: the canons of good taste
a standard to judge by; criterion
a body of rules, principles, criteria, etc.
the books of the Bible officially accepted by a church or religious body as divinely inspired
the works ascribed to an author that are accepted as genuine
the complete works, as of an author
those works, authors, etc. accepted as major or essential: the Victorian canon
Eccles. the fundamental and essentially unvarying part of the Mass, between the Preface and Communion, that centers on consecration of the bread and wine
a list of recognized saints as in the Roman Catholic Church
Music
a contrapuntal device in which a melody introduced in one voice is restated in one or more other voices that overlap the first and successive voices in continuous and strict imitation
a composition so constructed
noun
a member of a clerical group living according to a canon, or rule
a clergyman serving in a cathedral or collegiate church