笑逐颜开（笑逐顔開）　

◎ 笑逐颜开 xiàozhú-yánkāi

[beam with smiles;be all smiles;be wreathed in smiles;smile happily] 笑容满面,喜形于色

宋江见了,喜从天降,笑逐颜开。——《水浒传》