concubine: [13] A concubine is etymologically a person with whom one goes to bed. It comes via Old French concubine from Latin concubīna, a compound noun formed from the prefix com- ‘with’ and cub-, the stem of the verb cubāre ‘lie down, go to bed’. Another derivative of this verb was Latin cubiculum, whose meaning ‘bedroom’ was carried through into English cubicle [15]; the more general ‘partitioned-off area’ did not emerge fully until the 20th century. => cubicle
