A Zyngite is a WWF Easter Egg. Certain (wrong) words will bring up a popup saying you have found a Zyngite (I've had it happen with dogg and lazer)
A Zyngite is a word that you play, thinking it should be a valid word to play in the game, but isn't! Examples are: CAVA, LAZER and PIXI. If you play one of these in Words with Friends, you will get a pop-up telling you that you have found a Zyngite.