To refuse to accept something as true; to regard someone's statement as false or untrustworthy.
From dis- + believe (Old English belyfan, 'to have faith in'). This verb emerged in the 15th century as English developed more precise vocabulary for expressing doubt.
Disbelieve is more active than just doubt — it's the choice to reject something as false, which is why it sounds accusatory when you say someone disbelieves you.
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