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,
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