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

death rate

Kyūjitai form of 効率 (“efficiency”)

birthrate

(mathematics) pi