Not disclosed or divulged, secret; kept secret; communicated only to the initiated. Now rare.

Kept from knowledge or observation; hidden, concealed. Of doctrines, ceremonies, language, signs, methods of procedure, remedies, and the like…

= acroamatic, adj.

Privately communicated by oral teaching to chosen disciples only; esoteric, secret.

= acroamatic, adj.

Of philosophical doctrines, treatises, modes of speech, etc.: Designed for, or appropriate to, an inner circle of advanced or privileged disciples…

= esoteric, adj.