in the same way; likewise; similarly — used to indicate similarity or agreement, often in written or formal contexts.
彼も同じくその計画に賛成した。
He also agreed with that plan.
私は遅刻しました。彼も同じく遅れた。
I was late. He was likewise late.
同じく注意してください。
Please take the same caution / be equally careful.