(Tıp, İlaç) The word indel is a portmanteau of insertion or deletion, referring to the two types of genetic mutation that are often considered together because of their similar effect and the inability to distinguish between them in a comparison of two sequences
That can not be removed, washed away, blotted out, or effaced; incapable of being canceled, lost, or forgotten; as, indelible characters; an indelible stain; an indelible impression on the memory
If you say that something leaves an indelible impression, you mean that it is very unlikely to be forgotten. My visit to India in 1986 left an indelible impression on me + indelibly in·del·ibly The horrors he experienced are imprinted, perhaps indelibly, in his brain