1. Lacking education or knowledge.
2. Showing or arising from a lack of education or knowledge: an ignorant mistake.
3. Unaware or uninformed: was ignorant of the drug's harmful effects.
[Middle English ignoraunt, from Old French ignorant, from Latin ignōrāns, ignōrant-, present participle of ignōrāre, to be ignorant, not to know; see gnō- in the Appendix of Indo-European roots.]
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2022 by HarperCollins Publishers. 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.