What was that word?

(Chapter 16 The Many Problems with Words in my book)

I was watching a movie and there was a man who was a passenger in a vehicle. It looked like there was someone driving him around. I thought for a minute about what the driver is called and all that I could come up with was “driver”. For now, that worked for me. A short time later the man introduced his out-of-town friend to his chauffeur. I know that I have heard that word before but for some reason I couldn't remember it.