1. The act of illustrating or the state of being illustrated: concepts that would benefit from illustration; an idea that lends itself to illustration.
2. A picture or image that is used to decorate or clarify a text.
3. An example that is used to clarify or explain something. See Synonyms at example.
4. Obsolete Illumination.
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2019 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.