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perusing as a side business; doing in addition to one's main work; running (businesses) simultaneously
side business; job on the side
彼は会社員としての本業と兼業で作家活動をしている。
He does writing as a side job alongside his main job as an office worker.
農家の多くは兼業で生計を立てているのが現状だ。
The reality is that many farmers make a living through side jobs.
兼業農家が増加傾向にある。
The number of part-time farming households is on the rise.