lemonade n.

"ovate, pale yellow citrus fruit," c. 1400, lymon, from Old French limon "citrus fruit" (12c.), which comes via Provençal or Italian from Arabic laimun, Persian limun. Apparently brought from India to the Levant by the Arabs 9c. or 10c.; the word is perhaps ultimately from an Austronesian word of the Malay archipelago, such as Balinese limo "lemon," Malay limaw "citrus fruit, lime" (compare lime (n.2)).

Meaning "person with a tart disposition" is from 1863. For the sense "worthless thing," see lemon (n.2). Slang meaning "a Quaalude" is 1960s, from Lemmon, name of a pharmaceutical company that once manufactured the drug. The surname is from Middle English leman "sweetheart, lover." Lemon-juice is attested from 1610s; the candy lemon-drop from 1807. The East Indian lemon-grass (1837) is so called for its smell.

word-forming element denoting an action or product of an action, via French, Spanish, or Italian, ultimately from Latin -ata, fem. past-participle ending used in forming nouns. The usual form in French is -ée. The parallel form, -ade, came into French about the 13c. via southern Romanic languages (Spanish, Portuguese, and Provençal -ada, Italian -ata), hence grenade, crusade, ballad, arcade, comrade, balustrade, lemonade, etc.

This foreign suffix ade has been so largely imported, and at a time when the French language had still a certain plastic force, that it has been adopted as a popular suffix, and is still employed to form a crowd of new words, such as promenade, embrassade, glissade, bourrade, &c. [Brachet, "Etymological Dictionary of the French Language," Kitchin transl., Oxford, 1882]

Latin -atus, past-participle suffix of verbs of the 1st conjugation, also became -ade in French (Spanish -ado, Italian -ato) and came to be used as a suffix denoting persons or groups participating in an action (such as brigade, desperado).