Meals are
Breakfast - obvious
Lunch - Midday meal that may be a full hot meal or a sandwich/soup light meal.
Dinner - Evening meal, full dinner usually hot.
Tea - Usually cold light meal eaten if lunch was a full dinner.
So you can have breakfast lunch and dinner or breakfast lunch and tea but never EVER breakfast dinner and tea. There will be many people coming on to say that this isnt correct, but they are wrong, WRONG WRONG :o
Supper is a snack you may have between dinner and bedtime.
Thinking about it, if you are so inclined you can have breakfast, lunch, afternoon tea about 4 ish (tea scones and sandwiches) to keep you going until dinner at about 8, but thats not common these days.
I watched an episode of Friends the other day where Rachel is try to cop off with the new neighbour and says she is going to a "Regatta Gala" except instead of saying Re-gatt-a Garla, she says Re-garta Gal-la. She gets the pronounciation completely the wrong way round, whats that all about?!