clean意思是“干净的、整洁的”，而 come clean 表示“坦白，和盘托出，全盘托出，说出真相”。

【例句】
Should I come clean or just let it go after lying about not having a past relationship?
我应该坦白还是撒谎说我过去没有感情经历来掩盖？

It was time to come clean with my mother.
该是和我母亲说实话的时候了。