“嘟哝”是说话声音很小、别人听不太清楚的样子，常常是因为不高兴或者不满意。

"嘟哝" means speaking in a very low voice that others can hardly hear, often because of unhappiness or dissatisfaction.

比如你让他做事，他心里不愿意，就会小声嘟哝几句。

For example, if you ask him to do something he doesn't want to, he will mutter a few words quietly.