Radha (Mahābhārata)

Radha was the foster mother of Karna,one of the central characters in the Hindu epic the Mahābhārata. She is not connected with goddess Radha. She was the wife of Adhiratha, chief charioteer of King Dhritrashtra. Kunti bore a son from Surya, the solar deity after accidentally invoking him but afraid of being an unwed mother she reluctantly abandoned the child. She placed the baby in a basket and set him afloat a river. The child later known as Karna was found and adopted by the couple. Adiratha and Radha became his foster parents. Karna as an adult expressed loyalty towards his foster mother as opposed to his royal birth mother Kunti who had abandoned him soon after birth. Hence, he is sometimes called Radheya, meaning Radha's son. She was also the mother of Shon. It was Guru Dronacharya who gave him the name karna.

...
Wikipedia