That Ācārya (religious preceptor), who propounds the secret and mystical meanings of the canonical texts and also prescribes the application of rules and exceptions.
āmnāya- āgamastasyotsargāpavādalakṣaṇo'rthastaṃvaktītyāmnāyārthavācakaḥ, pāramarṣapravacanārthakathanenāmigrāhako'kṣanisadyānujñāyī pañcama ācāryaḥ.
(TaBhā 9.6 Vṛ)