飞快 fēikuài very fast Definitions Defs Origin Strokes Stroke Words Sentences Sents fēikuài very fast 飞 飛 fēi verbadverb swiftly to move at high speed快 kuài adjective fast rapid; quick; at high speedfēikuài extremely sharp 飞 飛 fēi verbadverb swiftly to move at high speed快 kuài adjective sharp (of knives or tools) having a fine edge; keen