A garrulous person just won’t stop talking (and talking, and talking, and talking…).

Garrulous comes from the Latin word garrire for “chattering or prattling.” If someone is garrulous, he doesn’t just like to talk; he indulges in talking for talking’s sake — whether or not there’s a real conversation going on. If you discover that you have a garrulous neighbor sitting next to you on the plane, you might just want to feign sleep, unless you really want to hear everything going through his mind for the entire trip.