Synonyms for Surreptitious:

• adj.

  •cloak-and-dagger (adjective)
  • hugger mugger.
  •secret (adjective)
  • backstairs,
  • hush-hush,
  • backdoor,
  • in ambush.
  •sneaky (adjective)
  • snide.
  •sneaky, secret (adjective)
  • clandestine,
  • covert,
  • fraudulent,
  • furtive,
  • hidden,
  • hole-and-corner,
  • hush-hush,
  • on the sly,
  • private,
  • skulking,
  • sly,
  • sneaking,
  • stealthy,
  • unauthorized,
  • under wraps,
  • under-the-table,
  • undercover,
  • underhand,
  • veiled,
  • Slinking,
  • sub-rosa,
  • on the qt.
  •undercover (adjective)
  • stealth,
  • under cover,
  • hole-and-corner.
  •underground (adjective)
  • on the sly,
  • Subterrestrial.
  •underhand (adjective)
  • lubricious.

• n.

  •
  • classified,
  • confidential,
  • mysterious,
  • secretive,
  • shadowy.
  •clandestine (noun)
  • hidden,
  • private.
  •surreptitious (noun)
  • clandestine,
  • cloak-and-dagger,
  • concealed,
  • covert,
  • furtive,
  • hole-and-corner,
  • hush-hush,
  • lurking,
  • on the quiet,
  • secret,
  • skulking,
  • sneak,
  • sneaky,
  • stealthy,
  • undercover,
  • underground.

• Other synonyms:

  •
  • classified,
  • closed-door,
  • conspiratorial,
  • inwardly,
  • secretly,
  • shadowy,
  • shady,
  • surreptitiously,
  • under-the-counter,
  • close-mouthed.
  •
  • secretive,
  • unidentified,
  • tight-lipped.
  •
  • backstage,
  • closet,
  • sly,
  • sneaking.
  •
  • closed,
  • inside.
  •
  • intimate.
  •Other relevant words:
  • adulterated,
  • ambiguous,
  • artful,
  • awry,
  • back door,
  • backhanded,
  • backstage,
  • backstair,
  • backstairs,
  • belowground,
  • bogus,
  • cabinet,
  • calculating,
  • case,
  • catchpenny,
  • cautious,
  • circuitous,
  • clandestine,
  • classified,
  • close,
  • closed,
  • closed-door,
  • closet,
  • collusive,
  • concealment,
  • confidential,
  • confidentiality,
  • conspiratorial,
  • contraband,
  • counterfeit,
  • crafty,
  • cunning,
  • darkness,
  • deceitful,
  • deceptive,
  • designing,
  • devious,
  • disguised,
  • dishonest,
  • disorderly,
  • doggo,
  • esoteric,
  • evasive,
  • fabricated,
  • fabulous,
  • factitious,
  • false,
  • feigned,
  • feline,
  • fictitious,
  • fictive,
  • forged,
  • fornicator,
  • foxy,
  • fraudulent,
  • goat,
  • guileful,
  • hidden,
  • hole-and-corner,
  • illegal,
  • illegitimate,
  • illicit,
  • illusory,
  • implied,
  • importation,
  • in hiding,
  • indirect,
  • inside,
  • insidious,
  • insincere,
  • intimate,
  • invented,
  • inwardly,
  • ironical,
  • irregular,
  • jumbled,
  • lecher,
  • locker,
  • lubricious,
  • meretricious,
  • misleading,
  • mock,
  • mysterious,
  • mystic,
  • mystical,
  • oblique,
  • occult,
  • offhand,
  • on the sly,
  • orphic,
  • personal,
  • phony,
  • pinchbeck,
  • poaching,
  • pretended,
  • privacy,
  • private,
  • privy,
  • pseudo,
  • pussyfoot,
  • quiet,
  • reserved,
  • reticent,
  • roundabout,
  • sarcastic,
  • satyr,
  • scheming,
  • secluded,
  • secrecy,
  • secretive,
  • secretiveness,
  • secretly,
  • seducer,
  • shadowy,
  • shady,
  • sham,
  • sharp,
  • shifty,
  • sidelong,
  • sideways,
  • silence,
  • silent,
  • slick,
  • slippery,
  • sly,
  • smooth,
  • smuggling,
  • sneaking,
  • snide,
  • so-called,
  • soi-disant,
  • sophisticated,
  • spurious,
  • stealing,
  • stealth,
  • supposititious,
  • surreptitiously,
  • taciturn,
  • tec,
  • tinsel,
  • topsy-turvy,
  • treacherous,
  • tricky,
  • two-faced,
  • ulterior,
  • unauthorized,
  • unavowed,
  • uncommunicative,
  • under wraps,
  • under-the-counter,
  • under-the-table,
  • underhand,
  • underhanded,
  • underlying,
  • underneath,
  • undisclosed,
  • unexpressed,
  • unfavourable,
  • unfounded,
  • unidentified,
  • unobtrusive,
  • unofficial,
  • unrevealed,
  • unsound,
  • untrue,
  • veiled,
  • vulpine,
  • whoremonger,
  • wily,
  • Adulterer,
  • Chiseling,
  • Double dealing,
  • Elusory,
  • Plated,
  • Plotting,
  • Slinking,
  • Slinky,
  • Trickish,
  • hugger mugger,
  • behind-the-scenes,
  • Colorable,
  • Covinous,
  • Prowling,
  • Stealthful,
  • Subreptitious,
  • Subterrestrial,
  • unexposed,
  • tight-lipped,
  • misnamed,
  • pussyfooted,
  • finagling,
  • circumlocutionary,
  • close-mouthed,
  • huggermugger,
  • backdoor,
  • falsehearted,
  • bastard,
  • in ambush,
  • under cover,
  • not expressed,
  • in the wings,
  • make-believe,
  • not for publication,
  • paillard,
  • scamped,
  • sub-rosa,
  • on the qt,
  • ben trovato.

Antonyms for Surreptitious:

• adj.

  • sneaky, secret
    aboveboard, open, public.
  • Other antonyms:
    aboveboard, acknowledged, avowed, clear, evident, manifest, obvious, open, overt, patent, plain, public, straightforward, unclassified, unconcealed, undisguised, unrestricted.

• Other antonyms:

  • n.
    unconcealed.