A philosophical or religious position that rejects or denies certain aspects of faith or doctrine; skepticism toward established beliefs.
Possibly from Latin 'a-' (without) plus 'deus' (god), with the '-ism' suffix indicating a doctrine or system, though the word is quite rare and its etymology is uncertain.
This is one of those wonderfully obscure words that scholars are still not entirely sure about—which is fitting for a word that apparently means rejecting certainty.
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