Usage note:A suffix borrowed directly from Latin,
-trix has been used since the 15th century on feminine agent nouns that correspond to a masculine (in Latin) or generic (in English) agent noun ending in
-tor: aviator, aviatrix; legislator, legislatrix; orator, oratrix. Most nouns in
-trix have dropped from general use, so that terms like
aviatrix, benefactrix, legislatrix, oratrix, and
proprietrix occur rarely or not at all in present-day English. The forms in
-tor are applied to both men and women:
Her sister is the proprietor of a new restaurant. When relevant, sex is specified with the generic term:
Amelia Earhart was a pioneer woman aviator. Legal documents still use
administratrix, executrix, inheritrix, and the like, but these forms too are giving way to the
-tor forms.
See also -enne, -ess, -ette. 
