a.

1. 海绵状的；轻软的；富有弹性的
   It was spongy to the touch.

   这东西摸上去像海绵。

2. 多孔的；有吸水性的
3. 湿软的

adj.

1. like a sponge, especially in being porous, compressible, or absorbent.
2. (of metal) having an open, porous structure.
3. (of a motor vehicle's braking system) lacking firmness.