Karna of Mahabharata is always referred as Daanveer Karna but Yudhisthira, the eldest of the Pandavas, is never referred as Daanveer. One who performs philanthropy, charity or almsgiving even during the toughest situations in life referred as Daanveer. ‘Daan’ means alms and ‘Veer’ is a mentally and physically courageous person.
Arjuna, one of the Pandavas, was jealous of Karna because he threatened his title of greatest archer. Therefore he used keep an eye on all activities of Karna.
One day, Arjuna asked his best friend and Guru, Sri Krishna, Why Karna is Daanveer and not my elder brother Yudhishtira. My brother never hesitates when an opportunity to help arrives. He has performed donation as per his capacity.
To give the answer to Arjuna and to clear his doubts, Sri Krishna asked Arjuna to get a makeover. Both of them dressed like poor saints. It was the rainy season and there was torrential rain.
Both Arjuna and Sri Krishna in the guise of poor saints reached the home of Yudhisthira and asked him for dried sandalwood for havan. Yudhisthira said that due to heavy rain he would not be able to provide dried sandalwood as everything is drenched. They can come after the rains to collect dried sandalwood from him.
Next Arjuna and Sri Krishna went to the house of Karna and made the same demand of dried sandalwood.
Karna first asked them to take rest and have food. He promised them that he would arrange for dried sandalwood.
Arjuna wondered how Karna would be able to get dried sandalwood pieces in this heavy rain.
After the poor saints had their food, Karna broke his main door and bed. They were made of sandalwood.
Karna thus fulfilled the wish of the two saints and donated the number of dried sandalwood pieces they needed.
Arjuna then realized why Karna is known as Daanveer and Not Yudhishtira.