That murmurs (in various senses of the verb).

Of a bird: chattering, chirping; that chatters habitually.

Characterized or accompanied by murmuring; full of murmurs. Also as adv.

Like muttering; murmurous.

Of liquid: that simmers. Also applied to a vessel containing such liquid, food being cooked in it, etc. Of heat: such as to cause liquid to…

Re-echoing with low, subdued sounds.

That mutters; speaking indistinctly and in a low tone. Also figurative.