high-water markBrE /ˌhaɪ ˈwɔːtə mɑːk/ 🔊NAmE /ˌhaɪ ˈwɔːtər mɑːrk/ 🔊, /ˌhaɪ ˈwɑːtər mɑːrk/ 🔊 nouna line or mark showing the highest point that the sea or floodwater has reached 高水位线（海水或洪水所达到的最高水位）◆(figurative) the high-water mark of Parisian fashion (= the most successful time) 巴黎时装最流行的时期 ➡ compare low-water mark