Azerbaijan UK /ˌæz.ə.baɪˈdʒɑːn/US /ˌæz.əɹ.baɪˈdʒɑn/ noun2 •A country in the South Caucasus in Asia and Europe. Official name: Republic of Azerbaijan. Capital: Baku. •A region in northwestern Iran, where ancient Atropatene was located, encompassing the modern provinces of Ardabil, East Azerbaijan and West Azerbaijan.Tahmâsb Coli Khân went to Azerbâïjân, and having liberated its capital, Tabriz, […] — 1830