1. Of, relating to, or containing bile; biliary.
a. Characterized by an excess secretion of bile.
b. Relating to, characterized by, or experiencing gastric distress caused by a disorder of the liver or gallbladder.
c. Appearing as if affected by such a disorder; sickly.
3. Resembling bile, especially in color: a bilious green.
4. Having a peevish disposition; ill-humored.
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.