from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. Germinal tissue of Porifera that forms cores or developing mesoderms.
from The Century Dictionary and Cyclopedia
- n. In sponges, an indifferent germinal tissue forming the core or primitive mesoderm whence the true mesoderm and the endoderm both arise.
cœn- + o conjuncted with blast, from Ancient Greek: κοινός (koinos, "common") combined with βλαστός (vlastos, "germ"). (Wiktionary)