An item of footwear (4)
I believe the answer is:
sock
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">an item of footwear</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for sock that I've seen before include "Clothing; punch" , "Hit; garment" , "Hit hard; woollen item" , "Item of clothing" , "Hit hard - footwear" .)