Names of Korea

There are various names of Korea in use today, derived from ancient kingdoms and dynasties. The modern English name Korea is an exonym derived from the Goryeo period and is used by both North Korea and South Korea in international contexts. In the Korean language, the two Koreas use different terms to refer to the nominally unified nation: Chosŏn () in North Korea, and Hanguk () in South Korea.

The earliest records of Korean history are written in Chinese characters called hanja. Even after the invention of hangul, Koreans generally recorded native Korean names with hanja, by translation of meaning, transliteration of sound, or even combinations of the two. Furthermore, the pronunciations of the same character are somewhat different in Korean and the various Korean dialects, and have changed over time.

For all these reasons, in addition to the sparse and sometimes contradictory written records, it is often difficult to determine the original meanings or pronunciations of ancient names.

Until 108 BC, northern Korea and Manchuria were controlled by Gojoseon. In contemporaneous Chinese records, it was written as 朝鮮, which is pronounced in modern Korean as Joseon (조선). The prefixing of Go- (古), meaning "ancient," is a historiographical convention that distinguishes it from the later Joseon Dynasty. The name Joseon is also now still used by North Koreans and Koreans living in China to refer to the peninsula, and as the official Korean form of the name of Democratic People's Republic of Korea. The word is also used in many Eurasian languages to refer to Korea, such as Japanese, Vietnamese, and Chinese.

Possibly the Chinese characters phonetically transcribed a native Korean name, perhaps pronounced something like "Jyusin". Some speculate that it also corresponds to Chinese references to 肅愼 (숙신, suksin), 稷愼 (직신, jiksin) and 息愼 (식신, siksin), although these latter names probably describe the ancestors of the Jurchen.

...
Wikipedia