It is a Latin locution that is interpreted as "argument for veneration or respect", and it is a fallacy by which a fact is taken for granted only because it was said by someone considered suitable in the subject. This does not prove the veracity of the fact, even if it were true, and its validation is considered a cognitive bias, because it is customary to accept the decision of the one who has more knowledge (or is supposed to have it), but it would not be a demonstration. See magister dixit, argument from authority.
