Definition of mediatrix in English:
mediatrix
noun miːdɪˈeɪtrɪksˈmiːdɪətrɪks
Origin
Late 15th century; earliest use found in John Lydgate (c1370–c1449), poet and prior of Hatfield Regis. From post-classical Latin mediatrix, feminine form corresponding to classical Latin mediātor: see -trix.