CONCUBINE
concubine, courtesan, doxy, paramour
(noun) a woman who cohabits with an important man
Source: WordNet® 3.1
Etymology
Noun
concubine (plural concubines)
A sexual partner, especially a woman, to whom one is not or cannot be married.
A woman who lives with a man, but who is not a wife.
(chiefly historical) A slave-girl or woman, kept for instance in a harem, who is held for sexual service.
Synonyms
• (unmarried sexual partner): mistress, sprunk; see sexual partner or mistress
• (woman who lives with a man): cohabitor
• (slave-girl): odalisque
Source: Wiktionary
Con"cu*bine, n. Etym: [F., fr. L. concubina; con- + cubare to lie
down, concumbere to lie together, akin to E. cubit.]
1. A woman who cohabits with a man without being his wife; a
paramour.
Note: Concubine has been sometimes, but rarely, used of a male
paramour as well as of a female. Trench.
2. A wife of inferior condition; a lawful wife, but not united to the
man by the usual ceremonies, and of inferior condition. Such were
Hagar and Keturah, the concubines of Abraham; and such concubines
were allowed by the Roman laws. Their children were not heirs of
their father.
Source: Webster’s Unabridged Dictionary 1913 Edition