Having the quality of being difficult to delete, remove, wash away, blot out, or efface.
This ink spot on the contract is indelible.
This stain on my shirt is indelible.
Written with indelible pen.
(figurative) Incapable of being canceled, lost, or forgotten.
That horrible story just might make an indelible impression on the memory.
Incapable of being annulled.
November 7, 1678, Thomas Sprat, a sermon preached at the Anniversary Meeting of the Sons of Clergymen in the Church of St Mary-le-Bow
They are […] endued with indelible power from above.