The suffix in "lemonade" that also appears in "limeade" and "orangeade" is -ade.
In beverage names, -ade commonly signals a drink made from fruit flavoring, water, and usually a sweetener. The pattern extends beyond these examples to words such as cherryade and shandyade. It is a naming element rather than a separate ingredient, so the ending does not guarantee that a drink contains fresh fruit or has the same recipe in every country.
The ending ultimately traces back to the Latin suffix -ata and entered English through French, especially the word limonade. Lemonade itself has a long history: early lemon-based drinks were documented in medieval Egypt, while organized lemonade sellers operated in Paris by 1676.
A regional difference can create another source of confusion. In North America, lemonade usually means a still drink made with lemon juice, water, and sugar. In Britain and several other countries, lemonade commonly means a clear carbonated soft drink. The -ade ending, however, remains recognizable across both naming traditions.