Synonyms of the word

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 (obsolete) Withdrawn from general intercourse or notice; in retirement or secrecy; secluded.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.

arcanum

• n. A mystery or deep secret.
• n. An elixir or secret remedy.

clandestine

• adj. Done or kept in secret, sometimes to conceal an illicit or improper purpose.
• adj. (freemasonry, of a person or lodge) Not recognized as a regular member.

classified

• v. simple past tense and past participle of classify.
• adj. Formally assigned by a government to one of several levels of sensitivity, usually (in English) top secret,…
• adj. Not meant to be disclosed by a person or organization.
• n. (informal) A classified advertisement in a newspaper or magazine.

cloak-and-dagger

• adj. Marked by menacing furtive secrecy, often with a melodramatic tint or espionage involved.

concealed

• v. simple past tense and past participle of conceal.

confidential

• adj. Kept, or meant to be kept, secret within a certain circle of persons; not intended to be known publicly.
• adj. (dated) Inclined to share confidences.

covert

• adj. (now rare) Hidden, covered over; overgrown, sheltered.
• adj. (figuratively) Secret, surreptitious, concealed.
• n. A covering.
• n. A disguise.
• n. A hiding place.
• n. Area of thick undergrowth where animals hide.
• n. (ornithology) A feather that covers the bases of flight feathers.

enigma

• n. Something or someone puzzling, mysterious or inexplicable.
• n. A riddle, or a difficult problem.

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.

hidden

• v. past participle of hide.
• adj. That has been moved out of sight. Invisible or unapparent.
• adj. Obscure.
• adj. That has been hidden.

hole-and-corner

• adj. Conducted in secret; clandestine.

hugger-mugger

• adj. Secret, clandestine, sly.
• adj. Disorderly, chaotic, confused.
• n. (archaic) Secrecy.
• n. Disorder.
• adv. Secretly.
• adv. Confusedly, in a muddle.

hush-hush

• adj. Secret, not spoken of (or spoken of only in hushed whispers between insiders).
• n. secrecy; covert operation.

info

• n. (informal) Short form of the word information.

information

• n. Things that are or can be known about a given topic; communicable knowledge of something.
• n. The act of informing or imparting knowledge; notification.
• n. (law) A statement of criminal activity brought before a judge or magistrate; in the UK, used to inform…
• n. (obsolete) The act of informing against someone, passing on incriminating knowledge; accusation.
• n. (now rare) The systematic imparting of knowledge; education, training.
• n. (now rare) The creation of form; the imparting of a given quality or characteristic; forming, animation.
• n. (computing) […] the meaning that a human assigns to data by means of the known conventions used in its…
• n. (Christianity) Divine inspiration.
• n. A service provided by telephone which provides listed telephone numbers of a subscriber.
• n. (information theory) Any unambiguous abstract data, the smallest possible unit being the bit.
• n. As contrasted with data, information is processed to extract relevant data.
• n. (IT industry jargon) Any ordered sequence of symbols (or signals) (that could contain a message).

inward

• adj. Situated on the inside; that is within, inner; belonging to the inside.
• adj. (obsolete) Intimate, closely acquainted; familiar.
• adv. Towards the inside.
• n. (obsolete, chiefly in the plural) That which is inward or within; the inner parts or organs of the body;…
• n. (obsolete, chiefly in the plural) The mental faculties.
• n. (obsolete) A familiar friend or acquaintance.

mysterious

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

mystery

• n. Something secret or unexplainable; an unknown.
• n. Someone or something with an obscure or puzzling nature.
• n. (obsolete) A secret or mystical meaning.
• n. A religious truth not understandable by the application of human reason alone (without divine aid).
• n. (archaic outside Eastern Orthodoxy) A sacrament.
• n. (chiefly in the plural) A secret religious celebration, to which none were admitted except those who had…
• n. (Catholicism) A particular event or series of events in the life of Christ.
• n. A craft, art or trade; specifically a guild of craftsmen.

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.

perplexity

• n. The state or quality of being perplexed; puzzled or confused.
• n. Something that perplexes.
• n. A measurement in information theory: see Perplexity.

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.

privy

• adj. (now chiefly historical) Private, exclusive; not public; one's own.
• adj. (now rare, archaic) Secret, hidden, concealed.
• adj. With knowledge of; party to; let in on.
• n. An outdoor facility for urination and defecation, whether open (latrine) or enclosed (outhouse).
• n. A lavatory: a room with a toilet.
• n. A toilet: a fixture used for urination and defecation.
• n. (law) A partaker; one having an interest in an action, contract, etc. to which he is not himself a party.

secluded

• adj. Hidden, isolated, remote.
• v. simple past tense and past participle of seclude.

surreptitious

• adj. Stealthy, furtive, well hidden, covert (especially movements).

unacknowledged

• adj. Not acknowledged.

unavowed

• adj. Not avowed.

undercover

• adj. Performed or happening in secret.
• adj. Employed or engaged in spying or secret investigation.
• n. A person who works undercover.

underground

• adj. (not comparable) Below the ground; below the surface of the Earth.
• adj. Hidden, furtive, secretive.
• adj. Of music, art, etc, outside the mainstream.
• adv. Below the ground.
• adv. Secretly.
• n. (chiefly Britain) An underground railway.
• n. (with "the") A movement or organisation of people who resist political convention.
• n. (with "the") A movement or organisation of people who resist artistic convention.
• v. To route electricity distribution cables underground.