name used in the West for the currency of the former German Democratic Republic (East Germany), 1948, from German Ost "east" (see east) + Mark, name of a unit of currency (see mark (n.2)).

capital of Republic of Congo, named for French explorer Pierre Savorgnan de Brazza, who founded it in 1883. An Italian count, his title is from the Adriatic island of Brazza, now Brač in Croatia.

"the office or province of a palatine ruler," 1650s, from palatine + -ate (1). In England and Ireland, a county palatine; also used of certain American colonies (Carolina, Maryland, Maine).

"Bolshevik, ultra-radical, revolutionary," 1917, from red (adj.1), the color they adopted for themselves. The association in Europe of red with revolutionary politics (on notion of blood and violence) is from at least 1297, but got a boost 1793 with adoption of the red Phrygian cap (French bonnet rouge) as symbol of the French Revolution. The first specific political reference in English was in 1848 (adj.), in reports of the Second French Republic (a.k.a. Red Republic).

Red Army is from 1918;  Red China is attested from 1934. Red-baiting is attested by 1929. The noun meaning "a radical, a communist" is from 1851.

congress of the Polish republic, 1893 (with an isolated reference from 1690s), from Polish sejm "assembly," from *syn-imu, literally "a taking together," from *syn- "together" (see syn-) + PIE root *em- "to take."