1. A term used to describe a person who cannot or will not stop talking, no matter how boring or pointless their topic of conversation is
2. A person who describes to you the antics of their cat, Snowball, until your eyes glaze over

When someone won't STFU and keeps blabbering their inane chatter.

constant talk with no information value. unstoppable talking. saying alot but saying nothing at all, not to be confused with saying alot by saying nothing at all. meaningless and unstoppable talk. drug-induced chatter. politics. barf.

Someone who can't stop talking.

Talking too much, usually about something unimportant.

an imaginary medical problem that is supposed to account for someone talking too much

When someone won't STFU, and he doesn't realize that everyone stopped listening a long time ago.