"secret; intended to be communicated only to the initiated; profound," 1650s, from Latinized form of Greek esoterikos "belonging to an inner circle" (Lucian), from esotero "more within," comparative adverb of eso "within," from PIE *ens-o-, suffixed form of *ens, extended form of root *en "in." Classically applied to certain writings of Aristotle of a scientific, as opposed to a popular, character; later to doctrines of Pythagoras. In English, first of Pythagorean doctrines.
by 1807, from Latinized plural of Greek esoterikos "belonging to an inner circle, pertaining to those within" (see esoteric).
Proto-Indo-European root meaning "in."
It forms all or part of: and; atoll; dysentery; embargo; embarrass; embryo; empire; employ; en- (1) "in; into;" en- (2) "near, at, in, on, within;" enclave; endo-; enema; engine; enoptomancy; enter; enteric; enteritis; entero-; entice; ento-; entrails; envoy; envy; episode; esoteric; imbroglio; immolate; immure; impede; impend; impetus; important; impostor; impresario; impromptu; in; in- (2) "into, in, on, upon;" inchoate; incite; increase; inculcate; incumbent; industry; indigence; inflict; ingenuous; ingest; inly; inmost; inn; innate; inner; innuendo; inoculate; insignia; instant; intaglio; inter-; interim; interior; intern; internal; intestine; intimate (adj.) "closely acquainted, very familiar;" intra-; intricate; intrinsic; intro-; introduce; introduction; introit; introspect; invert; mesentery.
It is the hypothetical source of/evidence for its existence is provided by: Sanskrit antara- "interior;" Greek en "in," eis "into," endon "within;" Latin in "in, into," intro "inward," intra "inside, within;" Old Irish in, Welsh yn, Old Church Slavonic on-, Old English in "in, into," inne "within, inside."
"intense esoteric meditation through yoga," 1827, earlier "state of union with creation" (1795), from Sanskrit samadhi-, literally "a putting or joining together," from sam- "together" (from PIE root *sem- (1) "one; as one, together with") + a- "toward" + stem of dadhati "puts, places" (from PIE root *dhe- "to set, put").
"Jewish mystic philosophy," 1520s, also quabbalah, etc., from Medieval Latin cabbala, from Mishnaic Hebrew qabbalah "reception, received lore, tradition," especially "tradition of mystical interpretation of the Old Testament," from qibbel "to receive, admit, accept." Compare Arabic qabala "he received, accepted." Hence "any secret or esoteric science." Related: Cabbalist.
"expounder of sacred mysteries," 1670s, from Late Latin hierophantes, from Greek hierophantes "one who teaches the rites of sacrifice and worship," literally "one who shows sacred things," from hieros "sacred," from PIE root *eis-, forming words denoting passion (see ire) + phainein "to reveal, bring to light" (from PIE root *bha- (1) "to shine"). In modern use, "expounder of esoteric doctrines," from 1822.
"relating to knowledge," especially mystical or esoteric knowledge of spiritual things, 1650s, from Greek gnōstikos "knowing, good at knowing, able to discern," from gnōstos "known, perceived, understood," earlier gnōtos, from gignōskein "learn to know, come to know, perceive; discern, distinguish; observe, form a judgment," from PIE *gi-gno-sko-, reduplicated and suffixed form of root *gno- "to know."
title applied to an adept in Brahmanism, literally "great-souled," from Sanskrit mahatman, from maha "great" (from PIE root *meg- "great") + atman, "soul, principle of life," properly "breath" (see atman). In esoteric Buddhism, "a person of supernatural powers." In common use, as a title, a mark of love and respect. Said to have been applied to Gandhi (1869-1948) in 1915, perhaps by poet Rabrindranath Tagore. The earliest use of the word in English, however, is among the theosophists, who applied it to certain imaginary beings with preternatural powers (1884).