son·o·rous 
(sŏnər-əs, sōnər-əs, sə-nôrəs)
(sŏnər-əs, sōnər-əs, sə-nôrəs)adj.
1. Having or producing sound.
2. Having or producing a full, deep, or rich sound.
3. Impressive in style of speech: a sonorous oration.
4. (also sōnər-əs) Produced in the manner of a sonorant.
[From Latin sonōrus, from sonor, sound, from sonāre, to sound; see swen- in the Appendix of Indo-European roots.]
sono·rous·ly adv.
sono·rous·ness n.
Usage Note: Traditionally, sonorous was stressed on the second syllable, but the pronunciation with stress on the first syllable is now much more common in American English, with either a short o (sŏnər-əs) or a long o (sōnər-əs). In our 2016 survey, a significant majority of the Usage Panel—64 percent—preferred (sŏnər-əs), while 26 percent preferred (sōnər-əs) and only 9 percent of the Usage Panel preferred the traditional (sə-nôrəs) pronunciation.