General "secret":
* ひみつ (himitsu) - This is the most common and general word for "secret." It can be used in many contexts, from personal secrets to government secrets.
Other specific meanings:
* 内緒 (naisho) - This means "secret" in the sense of something you don't want others to know. It's often used when asking someone to keep something confidential.
* 秘密 (himitsu) - This is a more formal and literary word for "secret." It's often used in official contexts or when discussing serious secrets.
* 隠された (kakusareta) - This means "hidden" and can also be used to refer to a secret, especially one that is being kept hidden from others.
* 謎 (nazo) - This means "mystery" or "enigma" and can also be used to refer to a secret that is difficult to uncover.
The best word to use will depend on the specific situation and the level of formality required.