a personal or private matter / selfishness / privacy, secrecy / (women's speech, obsolete) a brother-in-law

personal, private / secret

(formal) first-person singular pronoun: I, me

Alternative spelling of 私達 (“we; us”)

(idiomatic) to hold the key (to)

(Internet slang) protected account (on social media, especially Twitter and Instagram)

to lock (a door, etc.) / (Internet slang) (of a SNS account) to change privacy setting to limited people and posts and/or profiles can be seen by limited people.

black key (of a piano, etc.)

white key (of a piano, etc.)

(cryptography) secret key