Synonyms of the word

esoteric

• adj. intended for or likely to be understood by only a small number of people with a specialized knowledge…
• adj. Having to do with concepts that are highly theoretical and without obvious practical application; often…
• adj. Confidential; private.
• n. An esoteric doctrine or treatise; esoteric philosophy.
• n. One who believes, or is an initiate, in esoteric doctrines or rites.

abstruse

• adj. (obsolete) Concealed or hidden out of the way; secret.
• adj. Difficult to comprehend or understand; recondite; obscure; esoteric.

arcane

• adj. understood by only a few.
• adj. obscure, mysterious.
• adj. requiring secret or mysterious knowledge to understand.

cabalistic

• adj. Of or relating to a cabal; secretive and cliquish.
• adj. Of or relating to Kabballah.

cryptic

• adj. Having hidden meaning.
• adj. Mystified or of an obscure nature.
• adj. Involving use of code or cipher/cypher.
• adj. (zoology) Well camouflaged; having good camouflage.
• adj. (biology) Apparently identical, but actually genetically distinct.
• n. (informal) A cryptic crossword.

cryptical

• adj. cryptic.

deep

• adj. (heading, of a physical distance) Extending far away from a point of reference, especially downwards.
• adj. (heading, intellectual, social) Complex, involved.
• adj. (sound, voice) Low in pitch.
• adj. (of a color) Dark and highly saturated.
• adj. (sleep) Sound, heavy (describing a state of sleep from which one is not easily awoken).
• adj. Immersed, submerged (in).
• adj. Muddy; boggy; sandy; said of roads.
• adv. Deeply.
• n. (literary, with "the") The deep part of a lake, sea, etc.
• n. (rare) A deep shade of colour.
• n. (US, rare) The profound part of a problem.
• n. (with "the") The sea, the ocean.
• n. (cricket) A fielding position near the boundary.

kabbalistic

• adj. Alternative spelling of cabalistic.

mysterious

• adj. Of unknown origin.
• adj. Having unknown qualities.
• adj. Difficult to understand.
• adj. Deliberately evasive or enigmatic.

mystic

• adj. Of, or relating to mystics, mysticism or occult mysteries; mystical.
• adj. Mysterious and strange; arcane, obscure or enigmatic.
• n. Someone who practices mysticism.

mystical

• adj. Relating to mystics or mysticism.
• adj. Having a spiritual significance that transcends human understanding.
• adj. Inspiring a sense of spiritual mystery, awe, and fascination.

occult

• v. (transitive, astronomy) To cover or hide from view.
• v. (transitive, rare) To dissimulate, conceal, or obfuscate.
• adj. (medicine) Secret; hidden from general knowledge; undetected.
• adj. Related to the occult; pertaining to mysticism, magic, or astrology.
• adj. Esoteric.
• n. (usually with "the") Supernatural affairs.

private

• adj. Belonging to, concerning, or accessible only to an individual person or a specific group.
• adj. Not accessible by the public.
• adj. Not in governmental office or employment.
• adj. Not publicly known; not open; secret.
• adj. Protected from view or disturbance by others; secluded.
• adj. Not traded by the public.
• adj. Secretive; reserved.
• adj. (US, of a room in a medical facility) Not shared with another patient.
• n. The lowest rank of the army.
• n. A soldier of the rank of private.
• n. (in plural privates) A euphemistic term for the genitals.
• n. (obsolete) A secret message; a personal unofficial communication.
• n. (obsolete) Personal interest; particular business.
• n. (obsolete) Privacy; retirement.
• n. (obsolete) One not invested with a public office.
• n. (usually in the plural) A private lesson.

qabalistic

• adj. Alternative spelling of cabalistic.

recondite

• adj. (of areas of study and literature) Difficult, obscure; particularly.
• adj. (as a general term, somewhat archaic ; as a term in botany and entomology, obscure, rare) Hidden or removed…
• adj. (zoology, rare) Shy, avoiding notice (particularly human notice).
• v. (obscure, rare, transitive) to hide, cover up, conceal.

secret

• n. (countable, uncountable) Knowledge that is hidden and intended to be kept hidden.
• n. (uncountable) Something not understood or known.
• n. (archaic, in the plural) The genital organs.
• adj. Being or kept hidden.
• adj. (obsolete) Withdrawn from general intercourse or notice; in retirement or secrecy; secluded.
• adj. (obsolete) Faithful to a secret; not inclined to divulge or betray confidence; secretive.
• adj. (obsolete) Separate; distinct.
• v. (transitive) To make or keep secret.
• v. (transitive) To hide secretly.

sibylline

• adj. Of or pertaining to a sibyl or female oracle, especially the Cumaean Sibyl and the Sibylline Books.
• adj. (by extension) Having oracle-like predicting powers, clairvoyant.
• adj. mysterious.