Lengthen unnecessarily (3)
I believe the answer is:
pad
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">lengthen unnecessarily</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 pad that I've seen before include "Cushion" , "In slang, one's flat or bedsitter" , "Batsman's protection" , "Floating leaf of a lily" , "Number of sheets of paper fastened together" .)