Of, relating to, or having the character of esoteric oral teachings given to a select group of initiated students.
From 'acroamatic' + '-al' (adjectival suffix), an extended form emphasizing the quality of being acroamatic or pertaining to exclusive philosophical instruction.
This is essentially a fancy, longer way of saying 'acroamatic,' showing how Renaissance scholars liked to build increasingly elaborate synonyms—the extra syllable added no new meaning, just prestige.
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