n.

1. 褥垫，床垫[C]
   He kept his life's savings under his mattress.

   他将他一辈子的积蓄藏在床垫下。

n.

1. a fabric case filled with soft, firm, or springy material used for sleeping on.
2. Engineering  a flat structure of brushwood, concrete, or other material used as strengthening for foundations, embankments, etc.