mesoderm > define

noun

• The middle germ layer that develops into muscle and bone and cartilage and blood and connective tissue.
  • synonyms: mesoblast

• (n.) The layer of the blastoderm, between the ectoderm and endoderm; mesoblast. See Illust. of Blastoderm and Ectoderm.
• (n.) The middle body layer in some invertebrates.
• (n.) The middle layer of tissue in some vegetable structures.