Large cushion used as a seat (7)
I believe the answer is:
beanbag
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">large cushion used as a seat</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 beanbag that I've seen before include "a child might catch it" , "somewhere comfy to sit" , "Small cloth sack thrown in children's games" , "Large cushion used as a seat" , "support for student?" .)