Mussitate is a verb that means to talk indistinctly or mutter. 

The Latin word mussare (moose ARE ay) means ‘silence.’ It is believed that our word of the day is imitative in origin, meaning the word came to be because somebody thought it sounded like mumbling or muttering. Example:

I can always tell when my eight-year-old isn’t being totally honest. He avoids eye contact and begins to mussitate. All that mumbling and bumbling around is usually a sign that he’s not giving me the truth.