the company that sells the largest quantity of a particular kind of product 同类商品的销售大户；市场份额的最大占有者 We are the market leader in hi-fi. 我们是高保真音响设备的龙头企业。
a product that is the most successful of its kind 最畅销产品；同类商品中的佼佼者 The system is the market leader in the home PC market. 这套系统在家用电脑市场上是最畅销产品。