South Korea south·ko·rea uncommon noun 1. a republic in the southern half of the Korean Peninsula; established in 1948 SynonymsSouth KoreaRepublic of Korea Related words Word family South KoreanSouth Korean monetary unitSouth Korean won Broader terms Asian country Parts KoreaAsia Part of SeoulInchonKwangjuTaeguPusan WordNet 2.1 (Princeton University). WordNet 2.1 Copyright Princeton University. All rights reserved.