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 ESSENTIAL; BEING REQUIRED; BEING INDISPENSABLE Noun 必须的必须的，必不可少的，必要的 tính cần thiết
☆☆ ESSENTIAL; INDISPENSABLE; REQUIRED Determiner 必须的必须的，必不可少的，必要的 mang tính cần thiết