哝哝

wǒ men nóng nong le bàn tiān

我们哝哝了半天。

We talked in undertones for quite a while.

tā xīn qíng fēi cháng fán luàn zuǐ li gū gū nóng nong de zhòu mà zhe

她心情非常烦乱，嘴里咕咕哝哝地咒骂着。

She was in a right tizzy, muttering and swearing.