Esotericism

Esotericism or Esoterism derives from the Greek word esōterikos (ἐσωτερικός, from esōterō "within", "inner") meaning "pertaining to the more inward". Its antonym is "exotericism". It refers to a body of knowledge that is not public or attainable by the non-initiated.

Further reading

• Esotericism at Theosopedia