Or how to stop sounding like a pompous ass

I had to shake my head. Apropos, paradigm, myopic, maligned, rapier like,fondled,terminological exactitude. What was he thinking? It would have been bad enough if he was speaking to a panel of executives. In this case the words were inappropriate. After all, he was an announcer calling a hockey game.
Don’t get me wrong. I believe having a large and diverse vocabulary to be an asset. I believe that it is part of what determines how far you go in life.

I just also know that you have to speak the same language as your audience

This is sales (or public speaking) 101. Don’t talk above or below your audiance. Only use a $10 word if it better describes the situation. Above all don’t make your listener need a dictionary to understand you!