### Clue: Drive back by river in carriage having a cocktail (9)
### Answer: MARGARITA 
 ### Explanation: Definition: cocktail
 **Reversal of**(… back) RAM(to drive, say, a vehicle forcefully against, say, another vehicle) + [ R(abbrev. for "river") **contained in**(in) GAIT(carriage;the manner in which one walks) ] **plus**(having) A.