Definitions

1. noun

a simple multicellular sponge-like organism belonging to the class Sclerospongiae

“The discovery of spongin fossils provided valuable information about the evolution of the Earth’s ecosystem.”

2. noun

any of various simple multicellular marine sponges of the phylum Porifera

“Spongin is a type of sponge that has been used in various bath products for its cleansing properties.”