the middle layer of cells of an embryo, from which the skeletal, reproductive, muscular, vascular, connective, etc. tissues develop
Origin of mesodermmeso- + -derm
The middle embryonic germ layer, lying between the ectoderm and the endoderm, from which connective tissue, muscle, bone, and the urogenital and circulatory systems develop.
- mes′o·der′mal, mes′o·der′mic