### Clue: Short prince, the queen's alcoholic successor (6)
### Answer: CHASER 
 ### Explanation: Definition: alcoholic successor
 CHAS(short for "Charles", name of current prince, heir to the English throne) + ER(abbrev. for "Elizabeth Regina", queen and mother of the above mentioned prince).
Defn: Not a drunken heir, but a strong alcoholic drink taken after a weaker one.