|yu̇rō+ noun
Etymology: International Scientific Vocabulary ur- (I) + porphyrin
: any of four isomeric porphyrins C 20 H 6 N 4 (CH 2 COOH) 4 (CH 2 CH 2 COOH) 4 which contain acetic acid and propionic acid groups on the porphin nucleus and are closely related to the coproporphyrins and of which types I and III are found in urine especially in porphyria and type III is found also as the copper complex turacin