n. pl. ra·mi (-mī′)
1. A branch, as of a nerve or blood vessel, or a projecting part, as of a rotifer or crustacean.
2. A bony process extending like a branch from a larger bone, especially the ascending part of the lower jaw that makes a joint at the temple.
[Latin rāmus, branch; see wrād- in the Appendix of Indo-European roots.]
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.