n. pl. bo·lus·es
1. A round mass: "A dense bolus of trapped dolphins fills the frame" (Kenneth Browser).
a. A single, relatively large quantity of a substance, such as a dose of a drug, intended for therapeutic use and taken orally.
b. A concentrated mass of a substance administered intravenously for diagnostic or therapeutic purposes.
3. A soft mass of chewed food within the mouth or digestive tract.
[Medieval Latin bōlus, from Greek bōlos, lump of earth.]
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2018 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.