Extended short story (7)
I believe the answer is:
novella
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">extended short story</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for novella that I've seen before include "Slim volume of fiction" , "Short work of fiction" , "Short fictional piece" , "Small book" , "Short fictional work" .)