Piggy-bank feature (4)
I believe the answer is:
slot
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">piggy-bank feature</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 slot that I've seen before include "Long narrow aperture" , "Opening (for coins)" , "Long narrow opening" , "Narrow opening as in gaming machine" , "Long narrow slit" .)