indelible Definition

indelible
adj

1. Said eg of a mark or writing, or of a memory, etc: unable to be removed or rubbed out.

Thesaurus: enduring, indestructible, permanent, ineradicable, ineffaceable, lasting, ingrained, written in stone, inerasable, inexpungible; Antonym: erasable.
2. Said of a pen, pencil, ink, etc: designed to make an indelible mark.

Derivative: indelibly
adverb

Etymology: 16c: from Latin indelebilis, from delere to destroy.