Mawson, C.O.S., ed. (1870–1938). Roget’s International Thesaurus. 1922.

Class IV. Words Relating to the Intellectual Faculties
Division (II) Communication of Ideas
Section II. Modes of Communication

528. Concealment.

   NOUN:CONCEALMENT; hiding &c. v.; occultation, mystification.
  reticence, reserve, reservation; mental reservation, aside; arrière pensée [F.], suppression, evasion, white lie, misprision; silence (taciturnity) [See Taciturnity]; suppression of truth [See Falsehood]; underhand dealing; closeness, secret veness &c. adj.; mystery.
  seal of secrecy; freemasonry; screen [See Ambush]; disguise [See Ambush]; masquerade; masked battery; hiding place [See Ambush].
  CRYPTOGRAPHY, steganography; cipher, code, cable code; sympathetic ink, palimpsest.
  STALKING, still-hunt, hunt.
  STEALTH, stealthiness; obreption [obs.]; slyness (cunning) [See Cunning].
  SECRECY, latitancy [rare], latitation [obs.]; seclusion [See Seclusion. Exclusion]; privacy, secretness, hugger-mugger [archaic]; disguise, incognito (fem. incognita).
  MYSTICISM, occultism, supernaturalism; esotericism, esoterics, esotery.
  LATENCY [See Latency]; snake in the grass; secret [See Secret]; stowaway; blind baggage [slang].
  MASQUERADER, masker, mask, domino.
   VERB:CONCEAL, hide, secrete, put out of sight; lock up, seal up, bottle up.
  cover, screen, cloak, veil, shroud; cover up one’s tracks; screen from -sight, – observation; draw the veil; draw -, close- the curtain; curtain, shade, eclipse, throw a veil over; becloud, bemask; mask, disguise; ensconce, muffle; befog; whisper.
  keep- from, – back, – to oneself; keep -snug, – close, – secret, – dark; bury; sink, suppress; keep -from, – out of- -view, – sight; keep in -, throw into- the -shade, – background; stifle, hush up, smother, withhold, reserve; fence with a question; ignore [See Neglect].
  CODE, codify; use a -code, – cipher.
  KEEP A SECRET, keep one’s own counsel; hold one’s tongue (silence) [See Taciturnity]; make no sign, not let it go further; not breathe a -word, – syllable- about; not let the right hand know what the left is doing; hide one’s light under a bushel, bury one’s talent in a napkin.
  HOODWINK; keep -, leave- in -the dark, – ignorance; blind, – the eyes; blindfold, mystify; puzzle (render uncertain) [See Uncertainty]; bamboozle (deceive) [See Deception].
  BE CONCEALED &c. v.; suffer an eclipse; occult, retire from sight, couch; hide oneself; lie -hid, – in ambush, – perdu, – snug, – low [colloq.], – close; latitate [obs.]; seclude oneself [See Seclusion. Exclusion]; lurk, sneak, skulk, slink, prowl, gumshoe [slang, U. S.]; steal -into, – out of, – by, – along; play at -bopeep, – hide and seek; hide in holes and corners; stillhunt.
   ADJECTIVE:CONCEALED &c. v.; hidden; secret, latitant [rare], recondite, mystic, mystical, cabalistic or cabalistical, occult, dark; cryptic or cyptical, private, privy, in petto [It.], auricular, clandestine, close, close-mouthed, inviolate; tortuous.
  behind a screen [See Ambush]; under -cover, – an eclipse; in ambush, in hiding, in disguise; in a -cloud, – fog, – mist, – haze, – dark corner; in the -shade, – dark; clouded, wrapt in clouds; invisible [See Invisibility]; buried, underground, perdu; secluded [See Seclusion. Exclusion].
  UNDISCLOSED [See Disclosure], untold [See Information]; covert (latent) [See Latency]; mysterious (unintelligible) [See Unintelligibility].
  INVIOLABLE, irrevealable, confidential; esoteric; not to be spoken of.
  FURTIVE, obreptitious, stealthy, feline; skulking &c. v.; surreptitious, underhand, hole and corner [colloq.]; sly (cunnin) [See Cunning]; secretive, clandestine, evasive; reserved, reticent, uncommunicative, buttoned up; close, – as wax; taciturn [See Taciturnity].
   ADVERB:SECRETLY &c. adj.; in secret, in private, in one’s sleeve, in holes and corners [colloq.]; in the dark &c. adj.
  januis clausis [L.], with closed doors, à huis clos [F.]; hugger-mugger, in hugger-mugger [archaic], à la dérobée [F.], under the -cloak of, – rose, – table; sub rosâ [L.], en tapinois [F.], in the background, aside, on the sly [colloq.], with bated breath, sotto voce, in a whisper, without beat of drum, à la sourdine [F.].
  BEHIND THE VEIL; beyond -mortal ken, – the grave, – the veil; hid from mortal vision; into the -eternal secret, – realms supersensible, – supreme mystery.
  CONFIDENTIALLY &c. adj.; in -, in strict- confidence; between -ourselves, – you and me; entre nous [F.], inter nos [L.], under the seal of secrecy; à couvert [F.].
  UNDERHAND, by stealth, like a thief in the night; stealthily &c. adj.; behind -the scenes, – the curtain, – one’s back, – a screen [See Ambush]; incognito; in camerâ [L.].
  1. It must go no further, it will go no further.
  2. Tell it not in Gath.—Bible
  3. Nobody the wiser.
  4. Alitur vitium vivitque tegendo.
  5. Let it be tenable in your silence still.—Hamlet
  6. But let concealment, like a worm i’ the bud, Feed on her damask cheek.—Twelfth Night
  7. Mysticism … a transcendent form of common sense.—Chesterton