indelible
/ɪnˈdeləbl/adjective
1- (of ink or a pen) making marks that cannot be removed（墨水, 笔迹）去不掉的, 擦不掉的。
1.1
- not able to be forgotten or removed难忘的; 消除不掉的：
the story made an indelible impression on me.
故事给我留下了难以磨灭的印象。
派生词
indelibility
nounindelibly
adverb词源
late 15th cent. （as indeleble）: from French, or from Latin indelebilis, from in- 'not' + delebilis （from delere 'efface, delete'）. The ending was altered under the influence of -IBLE.