Dhananjaya is one among the ten names of Arjuna in the Mahabharata. Arjuna narrates the meaning of his names to Uttara, son of Virata. Kaurava army had stolen the cows of Virata. To get them back, the son of Virata went to battlefield with Arjuna, who was disguised as Brihannada, as his charioteer.
On seeing the Kuru army, the prince is frightened and attempts to escape from the battleground. Brihannada stops him and reveals that he is Arjuna and he will fight against the Kauravas.
But the prince is not ready to believe Brihannada. He then wants to know the various names of Arjuna. To convince the frightened prince, Arjuna narrates all his ten names and how he got them.
Arjuna in the Mahabharat is known as Dhananjaya because he conquered various kingdoms and obtained their wealth. As he stood amidst the riches that he conquered, he was named Dhananjaya.
This incident is mentioned in the Go – Grahana Parva in the Mahabharata.
The ten names of Arjuna given in the Go – Grahana Parva in the Mahabharata are Arjuna, Phalguna, Jishnu, Kiriti, Shvetavahana, Bibhatasu, Vijaya,
Krishna, Savyasachi and Dhananjaya.