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secret; private; surreptitious
彼は私かに転職活動を進めていたようだ。
It seems he had been secretly pursuing a job change.
私かな楽しみとして週末に陶芸教室に通っている。
As a private pleasure, I attend a pottery class on weekends.
二人は周囲に知られぬよう私かに会い続けた。
The two continued to meet in secret so no one would find out.