Definitions for "Concubine"
A woman who cohabits with a man without being his wife; a paramour.
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.
a "mistress". A female that serves a master sexually. Not a wife.
a recognized relationship in law and custom
a legal sexual partner without inheritance rights