1. A city of northwest France on an inlet of the Atlantic Ocean. Its large sheltered harbor was built in 1631 by Cardinal Richelieu as a naval base.

2. Formerly Brest-Li·tovsk (-lĭ-tôfsk) A city of southwest Belarus on the Bug River near the Polish border. It was the site (1596) of a synod of Eastern Orthodox church leaders who broke with Constantinople and entered into communion with the Roman Catholic Church, thereby establishing the Eastern Catholic churches. The Treaty of Brest-Litovsk, a separate peace treaty between Russia and the German coalition in World War I, was signed here on March 3, 1918.