1、quack英[kwæk]美[kwæk],n.江湖郎中; 庸醫; (鴨子的)呱呱聲,嘎嘎聲; 冒牌醫生;vi.(鴨子)呱呱叫,嘎嘎叫。
2、[例句]Hard-working medical men may come to be almost as mischievous as quacks.辛勤工作的醫生可能變成江湖郎中那樣的騙子。