low-water mark

noun

1. 低潮线；低潮水位标记
   a line or mark showing the lowest point that the sea reaches at low tide

1. Two-thirds of Martha's Vineyard's beaches are privately owned under Massachusetts law, that means down to the low-water mark and keys to the gates of association beaches sell for hundreds of thousands of dollars.
   玛莎文雅岛上的三分之二海滩是私人拥有的根据马萨诸塞州的法律，这就意味着一直到低潮线为止的所有权。通向联合会海滩大门的钥匙可以卖到数十万美金。
2. Hydrological Characteristics of Two Typical Subalpine Forests in The Upper Reaches of Minjiang River it is very dry this year, and the low-water mark of the Yellow River drops.
   岷江上游两种亚高山林分枯落物层水文特征研究今年气候干旱，黄河的枯水期提前了！
3. It is very dry this year, and the low-water mark of the Yellow River drops.
   今年气候干旱，黄河的枯水期提前了！

noun

1. a line marking the lowest level reached

2. an extreme state of adversity

   Synonym:    nadir