A beautiful young woman from Shunem who was sent to care for King David during his last days (1 Kings 1:1–4). After David’s death, Adonijah asked his half-brother, King Solomon, to marry Abishag. At that time, to take the concubine of a deceased king was to claim you were the next king (a concubine is a woman who lived with a man and had a relationship like a wife but without the full rights of marriage). Adonijah's request made Solomon angry and he ordered Adonijah to be killed (1 Kings 2:13–25).
Abishag
From Tyndale Bible Dictionary, adapted by Mission Mutual. CC BY-SA 4.0.