pronephros

noun

pro·​neph·​ros (ˌ)prō-ˈne-frəs 

-ˌfräs

: either member of the first and most cranial pair of the three successive paired vertebrate renal organs that functions in the adults of amphioxus and some lampreys, functions temporarily in larval fishes and amphibians, and is present but nonfunctional in embryos of reptiles, birds, and mammals compare mesonephros, metanephros

pronephric

(ˌ)prō-ˈne-frik 

adjective

Word History

Etymology

New Latin, from Greek pro- + nephros kidney — more at nephritis

First Known Use

1877, in the meaning defined above

Medical Definition

pronephros

noun

pro·​neph·​ros (ˈ)prō-ˈnef-rəs, -ˌräs 

plural pronephroi -ˌrȯi 

: either member of the first and most cranial pair of the three paired vertebrate renal organs that functions in the adults of amphioxus and some lampreys, functions temporarily in larval fishes and amphibians, and is present but nonfunctional in embryos of reptiles, birds, and mammals compare mesonephros, metanephros