1 (wiktionary) 2 (vi.wikipedia) 3 (en.wikipedia) 4 (glosbe)

Core Words Familarize yourself with the 'core words'.
Compounds Expand your vocabulary by studying more complex words built by the 'core words'.
Wordsense Learn about the wordsenses of the english term.

ETYMOLOGY

KOREAN 3.0 Eng Wordtype Etym. Gb Vie
☆ BEING UNKNOWN Noun 不明不明，不清楚，不详 sự không minh bạch, sự không rõ ràng
☆ INDISTINCT; OBSCURE Adjective 不分明 하다 不明，不清楚 không rõ ràng