The more creditable explanations are:
1.Coquetier is the French name for egg cup, in which a Frenchman is said
to have served mixed drinks to his guest. In time they came to ask for his
coquiers and the name was corrupted to cocktails.
2. An old French recipe containing mixed wines, called coquetel, was perhaps
carried to America by General Lafayette in 1777.
3. One Betsy Flanagan of Virginia is believed to have served a handsome
soldier a mixed drink containing all the colours of a cock's tail. He named
it 'cock-tail'.
4. The centuries-old expression 'cocked tail' describes a horse or person displaying high spirits. It naturally follows that a beverage seen to raise people's spirits would be called a cocktail.
The actual root of the term is most likely to have come from a two-word
expression, which leaves number 4 the favourite because it alone accounts
for the use of 'stimulating' in the original definition.