schoolmistress

[skool-mis-tris] /ˈskulˌmɪs trɪs/
noun
1.
a woman who presides over or teaches in a school.
Origin
1490-1500; school1 + mistress
Usage note
See -ess.
British Dictionary definitions for schoolmistress

schoolmistress

/ˈskuːlˌmɪstrɪs/
noun
1.
a woman who teaches in or runs a school
Derived Forms
schoolmistressy, adjective