1. Impossible to remove, erase, or wash away; permanent: indelible ink.
2. Making a mark not easily erased or washed away: an indelible pen for labeling clothing.
3. Unable to be forgotten; memorable: an indelible memory.
[Alteration of earlier indeleble, from Latin indēlēbilis : in-, not; see IN-1 + dēlēbilis, capable of being effaced (from dēlēre, to wipe out).]
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2020 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Indo-European & Semitic Roots Appendices
Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:
The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.