### Clue: Youngster given drug on lump of sugar? (4)
### Answer: CUBE 
 ### Explanation: Definition: lump of sugar
 CUB(a youngster/the young of a carnivorous mammal such as a fox) **plus**(given) E(abbrev. for the drug, Ecstasy).
Defn: …, usually in the shape of, well, a cube.