### Clue: Beginner returning favour … (4)
### Answer: NOOB 
 ### Explanation: Definition: Beginner
 **Reversal of**(returning) BOON(a favour or request asked of someone).
Defn: One who is inexperienced in a particular activity, especially in computing or Internet usage.
One of those clues that requires a checking letter to confirm which end of the clue is the definition.