Synonyms and related words :
abstract, abstruse, arcane, arcanum, beclouded, behind the curtain, behind the scenes, blind, buried, by stealth, cabala, cabalistic, camouflaged, censored, clandestine, classified, classified information, close, closed, closemouthed, clouded, concealed, confidence, confidential, confidential communication, confidentially, covered, covert, cryptic, cryptographic, dark, deep, deep-seated, devious, discreet, disguised, eclipsed, encrypted, enigma, enigmatic, esoteric, esoterica, evasive, furtive, furtively, genitals, guarded secret, heavy, hermetic, hermetics, hid, hidden, hole-and-corner, hugger-mugger, hush-hush, immanent, imperceptible, implanted, implicit, in a cloud, in a fog, in eclipse, in purdah, in secret, in the wings, inalienable, incommunicado, incomprehensible, indiscernible, indwelling, infixed, ingrained, inherent, inner, insensible, internal, intrinsic, invisible, inward, inwrought, irreducible, latent, lonesome, mysterious, mystery, mystery of mysteries, mystical, obfuscated, obscure, obscured, occult, on the sly, out of sight, out-of-the-way, parts, personal matter, private, private matter, private parts, privately, privates, privileged communication, privity, privy, privy parts, profound, profound secret, pudenda, quiet, quietly, recondite, remote, removed, resident, restricted, restricted information, retired, screened, sealed book, secluded, secluse, secretive, secretly, sequestered, shifty, shrouded, sightless, smothered, sneak, stealthily, stealthy, stifled, subjective, submerged, suppressed, surreptitious, surreptitiously, the occult, top secret, top-secret, transcendental, ulterior, unacknowledged, unalienable, unapparent, unbeheld, unbeholdable, unbreatheable, unchallengeable, uncommunicative, undeclared, under an eclipse, under cover, under house arrest, under security, under wraps, under-the-table, undercover, underground, underhand, underhanded, underneath, undiscernible, undisclosable, undisclosed, undivulgable, undivulged, unknown, unnoticed, unobserved, unperceivable, unperceived, unpublishable, unpublished, unquestionable, unrealized, unrevealable, unrevealed, unseeable, unseen, unspoken, untellable, untold, unutterable, unuttered, unviewed, unwhisperable, unwitnessed, viewless, wrapped in clouds