Esoteric

a. [ Gr. 'eswteriko`s, fr. 'esw`teros inner, interior, comp. fr. 'e`sw in, within, fr. 'es, e'is, into, fr. 'en in. See In. ] 1. Designed for, and understood by, the specially initiated alone; not communicated, or not intelligible, to the general body of followers; private; interior; acroamatic; -- said of discussions of technical topics and of the private and more recondite instructions and doctrines of philosophers. Opposed to exoteric. [ 1913 Webster ]

Enough if every age produce two or three critics of this esoteric class, with here and there a reader to understand them. De Quincey. [ 1913 Webster ]

2. Marked by secrecy or privacy; private; select; confidential; as, an esoteric purpose; an esoteric meeting. [ Webster 1913 Suppl. ]