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
☆☆ WITH MUCH TROUBLE Adverb 特意，难得，好容易 hiếm hoi lắm, khó khăn lắm