also: ないしょう
noun, noun which may take the genitive case particle 'no'
secret; secrecy; confidentiality
Refers to something kept hidden from others; often used in phrases like 内緒にする (keep secret) or 内緒の話 (confidential talk).
これは内緒の話だから、誰にも言わないでね。
This is a secret, so don't tell anyone.
She secretly prepared a present.
noun, noun which may take the genitive case particle 'no'
one's circumstances (esp. financial)
Rare, old-fashioned usage referring to one's personal or financial situation; now mostly replaced by 内情 or 事情.
In old novels, you see expressions like 'one's circumstances are difficult'.
noun, noun which may take the genitive case particle 'no'
inner realization; personal enlightenment
Only when written 内証 · Only with reading ないしょう
Buddhist term; refers to inner spiritual awakening or personal enlightenment. Read ないしょう.
In Zen Buddhism, the experience of inner realization is emphasized.
noun, noun which may take the genitive case particle 'no'
Only when written 内所
Rare, archaic meaning; written with 内所. Not used in modern Japanese.
In old documents, 内所 appears, referring to the kitchen.
Please keep that story secret from everyone.
I started a part-time job without telling my parents.
Let's keep it under wraps for now.
内密 is a stiffer, more official word for keeping something confidential (e.g. in business or legal contexts), while 内緒 is everyday and personal.
内緒 is a casual noun for keeping something hidden from specific people, while 密か is a more formal na-adjective describing an action or feeling done in secret.
内緒 is a casual word for a personal secret kept from specific people, whereas 内々 refers to handling matters informally within an organization or group.
Reading used for the Buddhist sense.
Kana spelling common in casual writing.
Rare kanji spelling for the 'kitchen' sense.