秘密的 backdoor; backstairs; cabinet; clandestine; closet; confidential a. secret; cryptical; delightful; furtive - open / forthright / brassy; furtively - candidly; heimlich adj; hole-and-corner; hugger-mugger; in secret; in the dark; inmost; inner; inside; interior; occult - bare / patent; pop; quiet; secretive; sly; sneak; stealthy; subterranean; surreptitious; undercover; underground; underhanded
秘密地 behind closed doors; between ourselves; clandestinely; closely; confidentially; entrenous; hugger-mugger; in close confinement; in corners; in secret; in the dark; on the quiet; on the side; on the sly; on the sneak; pope; privily; secretively; secretly; slily; sneakingly; surreptitiously; under one's hat; under the rose