1833, from lime (n.2) with ending as in lemonade. Earlier was lime punch (1774).
Entries linking to limeade
lime n.2
"greenish-yellow citrus fruit," 1630s, probably via Spanish lima or Portuguese limão, said to be via Arabic lima "citrus fruit," from Persian limun, in reference to the Persian lime, which might be a hybrid of the "Key" lime and the lemon.
The word is perhaps from or related to Sanskrit nimbu "lime." The Key lime is indigenous to India and the Malay archipelago (Arabs introduced it to the Levant, North Africa, Spain, and Persia in the Middle Ages); compare Malay (Austronesian) limaw "lime," also, generically, "citrus fruit," which might be the ultimate source. Yule and Burnell think the English got the word from the Portuguese in India. Lime-green as a color is by 1883.
lemonade n.
1660s, nativized from French limonade (17c.), which is from Italian limonata or else a French formation from limon; see lemon (n.1) + -ade. The earlier English spelling was lemonado (c. 1640) with false Spanish ending.