In the manner of a doctrinarian; in a way that is overly devoted to doctrines and rigid principles.
From doctrinarian + -ly, creating an adverb that modifies how an action is performed with a doctrinarian's inflexibility.
This word is so rare you'd have to actively search to find it used—it's the kind of 17th-18th century word that existed for precision but was too specialized to survive in modern usage.
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