Gaff (4)
I believe the answer is:
spur
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">gaff</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 spur that I've seen before include "railway siding" , "Provoke" , "Goad - incentive" , "Encourage" , "Impulse" .)