Thern is a surname. Notable people with the surname include: Jonas Thern (born 1967), Swedish association football manager and former professional player who played as a midfielder. Károly Thern (1817–1886), Hungarian composer, pianist, conductor and arranger. Simon Thern (born 1992), Swedish footballer. Willi and Louis Thern: Willi (1847–1911) and Louis (1848–1920), Hungarian pianists and teachers. See also. Thern Promontory, high ice-covered promontory at the south end of Eisenhower Range in Victoria Land.
https://en.wikipedia.org/wiki/Thern