### Clue: Sham flier heading north in gannet, acting like magpie? (9)
### Answer: PILFERING 
 ### Explanation: Definition: acting like magpie
 [ **Anagram of**(Sham) FLIER + N(abbrev. for "north") ] **contained in**(in) PIG(a greedy person/a gannet).
Defn: …, ie. one who obsessively collects things.