In a manner that opposes or is against religious beliefs, practices, or institutions.
From anti- (against) + religiously (in a religious manner). The adverb form developed in the 18th-19th centuries to describe actions or speech opposing religious authority or doctrine.
This word captures a specific historical moment when Enlightenment thinkers began openly challenging religious authority in public discourse—it's the linguistic marker of a massive cultural shift from private skepticism to public criticism.
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