The term "dead low tides" refers to the lowest level that a body of water can reach during the tidal cycle. Other synonyms for this phrase can include "low water mark," "low tide line," and "ebb tide." These terms are commonly used in maritime and coastal regions, as they are an important aspect of navigation and commerce. The opposite of "dead low tides" is "high tides," which refers to the highest level of water during the tidal cycle. Understanding these terms is crucial for anyone working or living near bodies of water, as they provide valuable information about the height and movement of tides.