### Clue: Grab stock from behind large, old boxes (5)
### Answer: LASSO 
 ### Explanation: Definition: Grab stock
 ASS(one's rear end;behind in North America, or "arse" in the UK) **contained in**(… boxes) [ L(abbrev. for "large") ] + O(abbrev. for "old") ].
Defn: To catch cattle with, well, a lasso.