rule, straight rod, standard
Something that is canonical is accepted as being accurate and authoritative--it possesses all the qualities that a thing of its kind should have.
When the Catholic Church canonizes someone, they are officially declared a saint; this word also refers to placing a work of art or literature in an accepted group of the best of its kind.
a rule or especially body of rules or principles generally established as valid and fundamental in a field or art or philosophy
treat as a sacred person
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