1. Of or relating to audible sound: a sonic wave.
2. Having a speed approaching or being that of sound in air, about 1,220 kilometers (760 miles) per hour at sea level.
3. Slang Extremely exciting and fast-paced: a sonic lifestyle.
[From Latin sonus, a sound; see swen- in the Appendix of Indo-European roots.]
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.