Mellifluous.

In a mellifluent manner.

Flowing like honey. / (figuratively) Sweet, smooth and musical; pleasant to hear (generally used of a person's voice, tone or writing style).

In a mellifluous manner; sweetly.

The property of being mellifluous.

(of a voice) The quality of sounding mellifluous; that is, the quality of sounding very smooth or pleasant.

plural of mellifluousness

plural of mellifluence