What is "oncken"

Oncken is a surname. Notable people with the surname include:

• Arthur Oncken Lovejoy, a German-born American philosopher
• August Oncken (1844–1911), a German economist ( German article)
• Hermann Oncken (1867–1945), a German historian
• Johann Gerhard Oncken (1800–1884), a pioneer German Baptist preacher
• Onno Oncken, a geologist
• Wilhelm Oncken (1835–1905), a German historian