AMBĀLIKĀ (1) The youngest of the three daughters of the King of Kāśī--Ambā, Ambikā and Ambālikā. Vicitravīrya, son of Śantanu married Ambikā and Ambālikā. The mother of this princess was Kausalyā.
2)
Pāṇḍu's Mother. Vicitravīrya died before children were born to his wives. To avoid the extinction of the family, Satyavatī, mother of Vicitravīrya summoned Vyāsa, her other son and asked him to beget a son for Ambikā. Vyāsa obeyed his mother half-heartedly. Ambikā did not like the dark-complexioned, crudely attired Vyāsa. Still owing to the Mother's pressure, she passively submitted to the act. As a result of their union was born Dhṛtarāṣṭra, who was blind from his birth. The grief-stricken mother called Vyāsa again and asked him to have union with Ambālikā this time. As Ambālikā's face was pale at the time of their union, a child with pale complexion was born to her. He was named Pāṇḍu. Having thus failed in both attempts, Satyavatī asked Ambikā to go to Vyāsa again. At night Ambikā secretly disguised her waiting-maid and sent her in her own place, to Vyāsa. The waiting-maid experienced exquisite pleasure in Vyāsa's company and as a result a most intelligent son was born to her. It was he who became the renowned Vidura.
[M.B., Ādi Parva, Chapter 106] .