arcane cabalistic censored clandestine classified close closed concealed covert cryptic dark enigmatic esoteric hermetic hidden hugger-mugger hugger-muggery hush latent mysterious occult restricted secret secretiveness secretness silence smothered stifled suppressed top secret ulterior unbreatheable under security under wraps under-the-table undisclosable undisclosed undivulgable undivulged unrevealable unrevealed unspoken untellable untold unutterable unuttered unwhisperable