Relating to, based on, or characteristic of doctrine; doctrinal.
From doctrine + -ary (from Latin -arius 'relating to'). This is an older, more archaic form of the adjective, now largely replaced by 'doctrinal' in modern usage.
'Doctrinary' is the ancestor of 'doctrinal'—English sometimes develops multiple forms of words, then standardizes on one, making older variants seem quaint or obsolete even though they're perfectly grammatical.
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