ETYM Old Eng. cuischun, quisshen, Old Fren. coissin, cuissin, French coussin, from (assumed) Late Lat. culcitinum, dim. of Latin culcita cushion, mattress, pillow. Related to Quilt, Counterpoint a coverlet.
A soft bag filled with air or a mass of padding such as feathers or foam rubber etc.

To protect from impact; SYN. buffer, soften.