### Clue: Wag rows in gym class with queen (9)
### Answer: PRANKSTER 
 ### Explanation: Definition: Wag
 RANKS(rows, as of taxis, say) **contained in**(in) PT(abbrev. for "physical training";gymclass) **plus**(with) ER(abbrev. for "Elizabeth Regina";the Queen).
Defn: A jocular person.