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
☆ UNDUTIFUL CHILD; UNFILIAL CHILD Noun 不孝子不孝子，不孝之子，逆子 đứa con bất hiếu, kẻ bất hiếu, bất hiếu tử