in a way that is impossible to remove by washing or in any other way

Ink had indelibly stained his shirt pocket. 墨水染了他的衬衫口袋，洗不掉了。

When you visit another country, your entry and departure dates will be indelibly marked in your passport. 去另一个国家时，你护照上会永久性地留下入境和出境日期。