The term "postmaster" is used to apply to both males and females. There are more female postmasters than male postmasters in the US.
Even though Postmistress would sound fun... Postmaster is always "Postmaster" regardless of the gender. :-)
postwoman
The noun postmistress is a gender specific noun for a female. The noun postmaster is a gender specific noun for a male.
Doctor is a neuter gender
Clot is not gender specific.
An emperor is the opposite in gender to an empress.
Opposite gender of Filipino: Filipina
The opposite gender of fraternity is sorority.
The opposite gender of giantess is giant.
Opposite gender to negro is-- NEGRESS
The opposite gender is girl.
The opposite of dairymaid is dairyman.