Lady's companions were well-bred women paid to accompany wealthy or titled women. They were given board and lodging, as well as a small allowance, and were expected to provide conversation and companionship, help entertain guests, and carry out minor domestic duties. The term was in use from the 18th century (possibly earlier) until approximately the middle of the 20th century.
Their social position was rather ambiguous as, even though they were not considered to be servants or employees in the strict sense, they did not have the same status as those they worked for. They often appear as characters in Agatha Christie's novels.