On Australian menus entrees = first course and mains = second course. It seems like in the USA the first course is called the appetiser and the second the entree. I thought the first course was entree because it's the "entrance" to the meal, that could be wrong!
I'm just curious, because I kept getting confused watching reruns of Hell's Kitchen and hearing them saying "We haven't got the entrees out!" When people are clearly eating 🙂 Does it come from when fine dining was more complicated with a million courses and we happened to pick different names to keep?