秘 密(ひみつ)

ひみつ

noun

secret

1. secret, confidential matter

Something that is kept hidden from others.

これは秘密(ひみつ)だよ。

This is a secret.

秘密(ひみつ)を守(まも)る。

To keep a secret.

秘密(ひみつ)にしておいて。

Keep it a secret.

友達(ともだち)に秘密(ひみつ)を打(う)ち明(あ)けた。

I confided a secret to my friend.

二人(ふたり)だけの秘密(ひみつ)にしようと約束(やくそく)したのに、みんなに知(し)られてしまった。

We promised to keep it a secret between just the two of us, but everyone found out.

秘密(ひみつ) means a secret or confidential matter. It functions as a noun and can modify other nouns with の (秘密(ひみつ)の場所(ばしょ), a secret place).

Common expressions

秘密(ひみつ)を守(まも)る: to keep a secret
秘密(ひみつ)にする: to keep something secret
秘密(ひみつ)を明(あ)かす: to reveal a secret
秘密(ひみつ)を打(う)ち明(あ)ける: to confide a secret
秘密(ひみつ)を漏(も)らす: to leak a secret

Similar words

ないしょ (内緒(ないしょ)): casual word for secret, often used among friends and family
極秘(ごくひ): top secret, strictly confidential (formal/official)

Usage

秘密(ひみつ) is neutral in register and works in both casual and formal contexts. ないしょ is softer and more colloquial — ないしょにしてね is the casual equivalent of 秘密(ひみつ)にしておいて.

Related Words

Compare: 内緒(ないしょ) (secret, confidentiality)

Compare: 極秘(ごくひ) (top secret, strictly confidential)

Compare: 機密(きみつ) (secrecy, classified information)

Compare: 隠密(おんみつ) (secrecy)

Compare: 内密(ないみつ) (confidential)

Related: 守秘(しゅひ) (confidentiality)

core

Added 2026.1.11 21:40 · Revised 2026.9.4 21:29

02500/02504_himitsu