What is the meaning of the name "Sanghamitra"

Sangha means gathering. Lord Buddha laid the foundation of Sangha, which was a gathering of Buddhist monks & nuns. Mitra means friend. Anyone who supported Buddhism, took part in the gathering & spread the teachings of Buddha were known as Sanghamitra.

Sanghamitra was also the name of the daughter of king Ashoka (who had embraced Buddhism after the Kalinga war ). She went to Srilanka to preach Buddhism.