Synonyms for Canonical (same or very similar meaning)
WordNet sense 1 (appearing in a biblical canon):
canonic
WordNet sense 2 (reduced to the simplest and most significant form possible without loss of generality):
basic
WordNet sense 3 (established or widely recognized as a model of authority or excellence):
standard
WordNet sense 4 (conforming to orthodox or recognized rules):
sanctioned
WordNet sense 5 (adhering to what is commonly accepted):
orthodox
From the ODE community, based on WordNet
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