Question

mistress

Accepted Answer

mis‧tress /ˈmɪstrəs, ˈmɪstrɪs/ noun [countable]
1a woman that a man has a sexual relationship with, even though he is married to someone else:
The Prince had shocked society by living openly with his mistress.
2British English old-fashioned a female teacher → master:
the new English mistress
3the female owner of a dog, horse etc → master
4old-fashioned the female employer of a servant → master:
The maid looked nervously at her mistress.
5be (a/the) mistress of something if a woman is a mistress of something, she is in control of it, highly skilled at it etc → master:
She appeared to be very much the mistress of the situation.
6Mistress old use used with a woman’s family name as a polite way of speaking to her → master
THESAURUS
girlfriend a girl or woman that you have a romantic relationship with, especially for a fairly long time: Katherine was his first girlfriend.
partner the person you are married to, or the person you are living with and having a sexual relationship with: He brought his partner along to the party.
old flame informal someone who was your girlfriend or boyfriend in the past: I found a love letter from one of his old flames.
mistress a woman that a man has a sexual relationship with even though he is married to someone else. Often used when the man is famous or powerful: The president had a mistress for many years.
lover someone who you have a sexual relationship with, but who you are not married to: He was going to meet his secret lover.
fiancée the woman who a man is going to marry: Rod plans to marry his fiancée later this year.
ex informal a man's former wife or girlfriend: My ex looks after the children on Thursdays.
be going out with somebody if you are going out with a girl or woman, she is your girlfriend: She's going out with a guy she met at work.

Mistress Woman Relationship Man Sexual Married Female Master