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
☆☆ THUNDER Noun 雷 sấm
☆☆ SHOWER Noun 雷阵雨 cơn mưa rào
☆ LIGHTNING Noun 雷电 sấm chớp