When someone begins
talking while you are already
talking and interrupts you. The word can also be applied in situations where people are not supposed to talk i.e at an inappropriate
time, during a moment of silence, or even during a movie.
The phrase comes from "jaywalking" when people who cross the street when they are not supposed to and interrupt the flow of traffic.
1. Dude would you
quit jaytalking, I'm trying to tell
a joke.
2. That guys a total jaytalker, he interrupts me every
couple seconds.