Question: How do you say lemonade in French? Not Limonade, but the drink were you mix water with lemon juice and sugar?
Answer: I believe most people would call that citronade.
These days ordering a limonade in a café will probably get a you a bottle of carbonated lemon flavored soda. However, the difference between the two terms according to the dictionary is that limonade is made with carbonated water, and citronade is made with plain water.