Carpenter's nail (4)
I believe the answer is:
brad
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">carpenter's nail</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for brad that I've seen before include "-- Pitt, US actor" , "Fixer" , "One to get hammered" , "Small tapered nail" , "Small-headed nail" .)