秘露[peruu] Peru
極秘[gokuhi] absolute secrecy
軍事秘密[gunjihimitsu] military secret
厳秘[genpi] strict secret
公然の秘密[kouzennohimitsu] open secret

社外秘[shagaihi] company secret
神秘[shinpi] mystery
神秘学[shinhigaku] occultism (Western)
神秘的[shinpiteki] mysterious
秘める[himeru] to hide

永訣[eiketsu] last farewell
訣別[ketsubetsu] separation
秘訣[hiketsu] secret (method, trick, etc.)

要訣[youketsu] main point
訣辞[ketsuji] words of parting
訣絶[ketsuzetsu] breaking off a relationship