Yap means to talk too much in an annoying or meaningless way. When someone yaps, they keep chattering on and on without saying anything important. You might hear someone complain, “He wouldn't stop yapping about his new video game” or “Stop yapping and let me concentrate.”

Think of how a tiny dog yaps loudly at everything: that's the same energy as someone who talks constantly without much purpose. When you call someone a yapper, you're saying they talk way more than they listen.

Yap can also be a playful insult between friends. If your friend says, “Quit your yapping,” they might be joking around while also hinting that you should get to the point. The key difference between yapping and regular talking is that yapping feels excessive and tiresome to the people listening.

As a noun, a yap can also mean a short, sharp bark or a quick, high-pitched shout, especially from a small dog.