Early 17th century; earliest use found in Henry Cockeram (fl. 1623–1658), lexicographer. From classical Latin dictātrīx, feminine form corresponding to dictātor from dictāt-, past participial stem of dictāre + -trīx.
Definition of dictatrix in US English:
dictatrix
noundɪkˈteɪtrɪks
A female dictator; = dictatress.
Origin
Early 17th century; earliest use found in Henry Cockeram (fl. 1623–1658), lexicographer. From classical Latin dictātrīx, feminine form corresponding to dictātor from dictāt-, past participial stem of dictāre + -trīx.