Small marrow (9)
I believe the answer is:
courgette
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">small marrow</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for courgette that I've seen before include "Small green vegetable" , "Variety of marrow" , "Zuccini" , "Small marrow" , "One of the vegetables" .)