mesonephros

noun, plural mes·o·neph·roi [mez-uh–nef-roi, mes-, mee-zuh-, -suh-] /ˌmɛz əˈnɛf rɔɪ, ˌmɛs-, ˌmi zə-, -sə-/. Embryology.

1. one of the three embryonic excretory organs of vertebrates, becoming the functional kidney of fishes and amphibians and becoming part of the tubules or ductules in the reproductive systems of higher vertebrates.

noun

1. the middle part of the embryonic kidney in vertebrates, becoming the adult kidney in fishes and amphibians and the epididymis in reptiles, birds, and mammalsSee also pronephros, metanephros

n. pl. mes•o•neph•roi (-nĕf′roi′)

1. The second of the three excretory organs that develop in a vertebrate embryo, replaced by the metanephros in higher vertebrates.wolffian body