INDELIBLE

[adjective] [not gradable] - (of dirty marks, ink etc.) impossible to remove by washing or in any other wayindelible inkThe blood had left an indelible mark on her shirt.(figurative) In his twenty years working for the company, Joe Pearson made an indelible mark (= had a strong influence) on it.(figurative) I have an indelible memory (= one that I will not forget) of that meeting with Anastasia.(figurative) The album is indelible evidence (= that which cannot be removed) that he remains the best blues singer of our time.