a personal or private matter / (by extension) selfishness

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

personal, private / secret

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

Alternative spelling of 私達 (“we; us”)

private; mine

one shouldn't bury one's head in the sand while leaving one's bottom exposed

conceal, cover up

(weaponry) hidden/concealed weapons

secret camera; hidden camera