adjective / verb
mellow
MEL-oh/ˈmeləʊ/
Pleasantly softened and free from harshness.
She looks mellow as she sits with an easy smile.

Etymology
Melwe first described ripe fruit as soft, sweet, and juicy. That pleasant ripeness extended to qualities perfected by maturing, then to rich, gentle sounds and genial moods.
In context
It's got rich, kind of oaky, vanilla, caramel stuff going on and is very mellow and smooth.
More examples
- The cheese has a rich, mellow flavor.
- The guitar's mellow tone suits this quiet song.
- He has mellowed with age and rarely loses his temper.
- Slow cooking mellows the sharp flavor of the onions.
Forms
mellow · mellower · mellowest · mellows · mellowed · mellowing
mellowness noun — A pleasant softness or relaxed quality.