The spines are slender and filled with a spongy material.

The interior was filled with red, spongy material.

Bone marrow, the spongy material inside your bones, makes new blood cells.

Nerf foam is made from a solid, spongy cellular material.

The real substance of the spoke was a spongy gray material.

The spongy material absorbed much of the impact, but Lwaxana still looked jolted.

A second piece of the same spongy material had been neatly folded on a smaller plate beside the first.

Sure enough, there was no blood, just a spongy material like foam plastic within the skull.

Whale bone: All bones are hollow, the cavity being filled with a spongy material.

To his immense relief, he saw that the whole crew of the Venture had come with him and were sitting on the same spongy material.