To utter words in a low voice with lips almost closed; murmur.

低声含糊发言；喃喃细语。

To sound with low, rumbling noises, as thunder.

发出低沉隆隆声(如雷声)。

To utter low and indistinctly.

发含糊不清之语；低而含糊地说。

Indistinct utterance; a murmur; a grumble.

低语；喃喃；抱怨。