Carpenter's item (4)
I believe the answer is:
nail
'carpenter's item' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for nail that I've seen before include "Hammered pin" , "Horny part of the digit" , "Detect or catch (a criminal) (colloq.)" , "Hammer's target" , "Hard plate at end of digit" .)