1. often rudiments
a. A fundamental element, principle, or skill, as of a field of learning: the rudiments of calculus.
b. Something in an incipient or undeveloped form: the rudiments of social behavior in children; the rudiments of a plan of action.
2. Biology An imperfectly or incompletely developed organ or part.
[Latin rudīmentum, from rudis, rough, unformed.]
ru′di·mental (-mĕntl) adj.
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2020 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.