high-water mark, high-water line 1. 高水位线；高潮线 2. 高水(或潮水、洪水)退后留下的水位痕迹 3. [常作 high-water mark] (事业等的)顶点，顶峰；最高纪录 His successful negotiation of the treaty was the high-water mark of his diplomatic career. 他在这项条约的谈判中获得成功，这是他外交生涯中的最大成就。 Unemployment stands at a high-water mark. 失业人数创下最高纪录。