1. A painful localized bacterial infection of the skin and subcutaneous tissue that usually has several openings through which pus is discharged.
a. A red precious stone, especially a deep-red garnet cut as a cabochon.
b. A mythical gemstone said to emit light even in total darkness.
[Middle English, from Old French, from Latin carbunculus, small glowing ember, carbuncle, diminutive of carbō, carbōn-, coal; see ker-3 in the Appendix of Indo-European roots.]
car·buncu·lar (-kyə-lər) adj.
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.