1843, from German Sorbe, from Slavic Serb, the national designation. Slavic people surviving in Lusatia, eastern Saxony, also known as Wends. Related: Sorbian (1836); earlier Sorabian (1788), from Medieval Latin Sorabi.
sorb (n.)
"fruit of the service tree," 1520s, from French sorbe, from Latin sorbum "service-berry" (small, edible fruit of the European mountain ash), from sorbus, of uncertain origin.