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
☆ FLUTTER Verb 飘扬，招展 tung bay, cuốn bay
☆ FLAP; FLUTTER; WAVE Verb 舞动，挥舞 bay phần phật
☆ KEEP WAVING; KEEP FLAPPING; KEEP FLUTTERING Verb 飘扬，飘舞 phần phật