first attested 1806; H.L. Mencken lists seven versions of its origin, perhaps the most persuasive is French coquetier "egg-cup" (15c.; in English cocktay). In New Orleans, c.1795, Antoine Amédée Peychaud, an apothecary (and inventor of Peychaud bitters) held Masonic social gatherings at his pharmacy, where he mixed brandy toddies with his own bitters and served them in an egg-cup. On this theory, the drink took the name of the cup. Used from 1920s of any mix of substances (e.g. fruit, Molotov). Cocktail party first attested 1928.
cocktail cock·tail (kŏk'tāl)
A mixture of drugs, usually in solution, for the diagnosis or treatment of a condition.
A treatment regimen that includes a combination of several drugs, to enhance their individual potency.