Blabber on is a phrase we use to describe someone who talks too much about something in a way that is not interesting or useful. If you're looking for some synonyms, we've got you covered. Instead of "blabbering on," you might say "rambling," "babbling," or "prattling." These words convey the sense that someone is talking aimlessly without much thought or direction. Another phrase you could use might be "going on and on," which emphasizes the length of their speech. Whatever phrase you choose, just remember that it's important to be mindful of how much you're talking and whether you're actually adding value to the conversation.