The word "jabbering" has a negative connotation and refers to excessive or incoherent talking, often without making much sense. It can also imply that the person is talking too much or at length without saying anything of substance.
Sentences with «jabbering»
They shouldn't listen to a lot of jabbering about what the market's going to do tomorrow or next week or next month, because nobody knows. (pbs.org)
He started jabbering on about alternative medicine. (politics.co.uk)
The journalistic jibber jabber of Marco Rubio and Rand Paul being serious candidates is nonsensical verbal diarrhea. (nystateofpolitics.com)