kuài
rapid
Phonosemantic compound. 忄 represents the meaning and 夬 represents the sound.
Evolution

Seal script
Shuowen (~100 AD)
Clerical script
Western Han dynasty (202 BC-9 AD)Regular script
ModernDefinitions
kuài
rapid, quick, speedy, fast; soon; rapid; quick; speed; rate; almost; to make haste; clever; sharp (of knives or wits); forthright; plainspoken; gratified; pleased; pleasant
Component uses
Sound component in 1 character (1 verified)
Sources