noun. the inner germ layer that develops into the lining of the digestive and respiratory systems.
- germ layer
Example sentences of the word endoderm
1. Noun, singular or mass
Cnidarians have only two body layers, the endoderm, and the ectoderm.
Roundworms are psuedocoelomate, which means they have a body cavity between their mesoderm and endoderm layers.