### Clue: A former police song about a setter (9)
### Answer: ARAUCARIA 
 ### Explanation: Definition: setter
  A + {RUC(Royal Ulster Constabulary, *former* name for the *police* force in Northern Ireland) + ARIA(*song*)} around(*about*) A.  Defn:  Pseudonym of a prolific crossword *setter *featured in the Guardian cryptics.  I cut my cryptic crossword teeth on Araucaria's Monkey Puzzles.  The word itself stands for a genus of trees, including the monkey puzzle, a conifer with edible nuts.