Prattle is a verb that means to talk at length in a foolish way.
Coming from the Low German word prate (PRATE) which has the same meaning as our word of the day, prattle is a word almost never used in a flattering way. Here’s an example:
After two hours of hearing the salesman prattle on about the car’s special features, I was fairly sure I had no interest in the new convertible. It wasn’t until he got beyond all the nonsense and onto the low discounted price that he actually had my interest.