The act of loving to hear oneself speak to such an extent, that they will prattle on endlessly while saying little of value. Oftentimes this prattling will be reflective of the speaker's misguided sense of worth, i.e: they think much higher of themselves than what is deemed appropriate, and have little difficulty consistently extolling their own virtue while others roll their eyes.
Avatar could have been an hour shorter, were it not for James Cameron's signature windbaggery.
I hope we won't have to put up with Steve's windbaggery at this party. It's one thing to brag about everything, but does anyone even care?