A cocktail is a combination of several things, and the theory of its origin is a combination of several disputed words. Though officially unknown in etymology, the most possible root is not the obvious one. According to a few sources, cocktail comes from the French word coquetier, which meant "egg-cup", describing the kind of glass the first cocktails were drunk out of. This would come from the French word coque, meaning "eggshell", if we eliminate the suffix -ier, which created the "cup" implication. Coque would come from Latin concha, meaning "shell" or "conch" (and, unsurprisingly, also the etymon of conch), and that most likely comes from an Ancient Greek word for "mussel". There are many other theories, but the second most plausible origin is that it comes from cock's ale, because early cocktails had chicken in them.
Adam Aleksic, a freshman studying linguistics at Harvard University, has been described as the internet's sixth most famous etymologist. He has disturbing interests in words, vexillology, geography, board games, limericks, and law, and he loves writing about himself in the third person.
The Etymology Nerd