indelible

1. ADJ If you say that something leaves an indelible impression, you mean that it is very unlikely to be forgotten. 難忘的[usu ADJ n]

My visit to India in 1986 left an indelible impression on me. 1986年的印度之行給我畱下了難忘的印象。

2. indeliblyADV [ADV with v]

The horrors he experienced are imprinted, perhaps indelibly, in his brain. 他經歷的恐怖事件在他腦海中刻下了深深的，也許是難以磨滅的印記。

3. ADJ Indelible ink or an indelible stain cannot be removed or washed out. (汙漬)洗不掉的[usu ADJ n]

It leaves indelible stains on clothes. 它會在衣物上畱下洗不掉的汙漬。

The message was written in indelible ink. 這條信息是用不褪色的墨水寫的。