The term 'mistress' is used to describe a variety of relationships, ranging from COURTESAN to PROSTITUTE. A COURTESAN is a woman who engages in a romantic relationship with a wealthy man for financial gain. A DOXY is a woman who is involved in a sexual relationship outside of marriage. A GIRLFRIEND is a FEMALE partner in a romantic relationship. An OWNER is a person who has control or possession of something. A FEMALE is an adult human FEMALE. A BELOVED is someone who is deeply loved and cherished. A PROSTITUTE is a person who engages in sexual activity for money. A SWEETHEART is a term of endearment for a loved one. A CONCUBINE is a woman who lives with a man without being married to him. A LOVER is a person who is in love with another. A hetaera is an ancient Greek COURTESAN.