1. A speech sound, such as (ē) or (ĭ), created by the relatively free passage of breath through the larynx and oral cavity, usually forming the most prominent and central sound of a syllable.
2. A letter, such as a, e, i, o, u, and sometimes y in the English alphabet, that represents a vowel.
[Middle English vowelle, from Old French vouel, from Latin (littera) vōcālis, sounding (letter), from vōx, vōc-, voice; see wekw- 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.