mistress
US /ˈmɪs.trəs/
UK /ˈmɪs.trəs/
1.
amante
a woman in a position of authority or control.
:
•
she is always mistress of the situation, coolly self-possessed
2.
amante
a woman (other than the man's wife) having a sexual relationship with a married man.
:
•
Elsie knew her husband had a mistress tucked away somewhere