1. The quality or state of being sonorous; resonance.
2. A sound.
3. Linguistics. The degree to which a speech sound is like a vowel. Plosives have the least sonority and vowels have the most.

The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.