coussin

In a sentence

• Ce coussin est très confortable.

  This cushion is very comfortable.

  Here, 'coussin' is used as a noun referring to a cushion, emphasizing its quality of comfort.

• J'ai acheté un coussin pour la décoration du canapé.

  I bought a cushion for the decoration of the sofa.

  In this sentence, 'coussin' describes an item purchased as a decorative addition to a piece of furniture.

• Sans ce coussin, ma chaise serait trop dure pour s'asseoir.

  Without this cushion, my chair would be too hard to sit on.

  In this example, 'coussin' is mentioned as an object improving comfort during use of another object, the chair.