that cannot be eliminated, forgotten, changed, or the like:
the indelible memories of war; the indelible influence of a great teacher.
making marks that cannot be erased, removed, or the like:
Alone among the celebrity journalists of the sixties… he has both given us indelible portraits of living people and brought ideas to vivid, eccentric life.
— Rhoda Koenig , “Tom Wolfe Rattles the Foundations of Modern Architecture,” New York , 1981
How had she remembered it all? She hadn’t made an effort–how had every dish remained so indelible after all conversations and glances had faded?
— Andrew Sean Greer , How It Was for Me: Stories , 2000
Indelible can be traced to the Latin indēlēbilis meaning “indestructible.” It entered English in the mid-1500s.