to talk continuously, especially informally
All that Edward does is talk yack.
Edward: it's kinda like the idea of dog years
you know like a dog is 5, but it's actually like 30 in dog years
there should be some kind of conversion for girls to guys cause you know, girls kind of peak early
so like a 26 year old guy is like an 18 year of girl
Me: SHUT THE YACK UP!
Less yack, more work.