Large cushion used as a seat (7)
I believe the answer is:
beanbag
'large cushion used as a seat' is the definition.
(I've seen this before)
This is all the clue.
(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?" .)