Synonyms and related words :
accessory, additional, alien, ambiguous, ancillary, another, arcane, auxiliary, barbarian, barbaric, barbarous, beyond, buried, cabalistic, censored, classified, close, closed, collateral, concealed, contributory, covert, cryptic, dark, enigmatic, equivocal, esoteric, exotic, exterior, external, extra, extraneous, extraterrestrial, extrinsic, farther, foreign, foreign-born, fresh, further, guarded, hermetic, hidden, hush-hush, intrusive, latent, more, more distant, mysterious, new, obscure, obscured, occult, other, outland, outlandish, outside, personal, plus, private, privy, remote, remoter, restricted, secret, shrouded, smothered, spare, stifled, strange, supernumerary, supplemental, supplementary, suppressed, surplus, surreptitious, thither, top secret, unbreatheable, under cover, under security, under wraps, underhanded, underlying, undisclosable, undisclosed, undivulgable, undivulged, unearthly, unexpressed, unrevealable, unrevealed, unspoken, untellable, untold, unutterable, unuttered, unwhisperable, yon, yonder