Esotericism or Esoterism is a term with two basic meanings.

  • In the dictionary sense of the term, "esoterism" signifies the holding of esoteric opinions or beliefs, and derives from the Greek ἐσωτερικός (esôterikos), a compound of ἔσω (esô): "within", thus "pertaining to the more inward", mystic. Its antonym is "exoteric".

  • In scholarly literature, the term designates a series of historically related religious currents including Gnosticism, Hermetism, magic, astrology, Kabbalah, alchemy, Rosicrucianism, Vajrayana Buddhism, the Christian Theosophy of Jacob Böhme and his followers, Illuminism, Mesmerism, Swedenborgianism, Spiritualism, and the theosophical currents associated with Helena Blavatsky and her followers. There are competing views regarding the common traits uniting these currents, not all of which involve "inwardness", mystery or secrecy as a crucial trait.

The dictionary defines esoteric as information that is understood by a small group or those specially initiated, or of rare or unusual interest. Esoteric items may be known as esoterica. Esotericism is defined as the holding of secret doctrines, the practice of limiting knowledge to a small group, or an interest in items of a special, rare, novel, or unusual quality.