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

実験台: laboratory bench

核実験: nuclear bomb test

a research student (i.e. a visiting or non-matriculating graduate student) / a researcher

researcher