sonorous (adj.) Look up sonorous at Dictionary.com
1610s, from Latin sonorus "resounding," from sonor "sound, noise," from sonare "to sound" (see sonata). Related: Sonorously; sonorousness. Earlier was sonouse (c. 1500), from Medieval Latin sonosus; sonourse "having a pleasing voice" (c. 1400), from sonor + -y (2).