Pronunciation: (su-nôr'us, -nōr'-, son'ur-us),[key] —adj. 1. giving out or capable of giving out a sound, esp. a deep, resonant sound, as a thing or place: a sonorous cavern. 2. loud, deep, or resonant, as a sound.
3. rich and full in sound, as language or verse.
4. high-flown; grandiloquent: a sonorous speech.