what is meant by 'seawater'?
It is water in the sea a characteristic of seawater is that it is salty.
Sea

While the constituents of table salt sodium and chloride make up about 85 percent of the solids in solution, there are also other metal ions such as magnesium and calcium, and negative ions including sulphate, carbonate, and bromide. Despite variations in the levels of salinity in different seas, the relative composition of the dissolved salts is stable throughout the world's oceans. Seawater is too saline for humans to drink safely, as the kidneys cannot excrete urine as salty as seawater. 
Although the amount of salt in the ocean remains relatively constant within the scale of millions of years, various factors affect the salinity of a body of water. Evaporation and by-product of ice formation (known as "brine rejection") increase salinity, whereas precipitation, sea ice melt, and runoff from land reduce it. The Baltic Sea, for example, has many rivers flowing into it, and thus the sea could be considered as brackish. Meanwhile, the Red Sea is very salty due to its high evaporation 
which of the following is not generally a factor in wave generation in the open ocean UNANSWERABLE what is the definition of 'sea'? The sea, the world ocean, or simply the ocean is the connected body of salty water that covers over 70% of Earth's surface.
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Sea [SEP] Seawater
The water in the sea was thought to come from the Earth's volcanoes, starting 4 billion years ago, released by degassing from molten rock. More recent work suggests much of the Earth's water may come from comets. A characteristic of seawater is that it is salty. Salinity is usually measured in parts per thousand (‰ or per mil), and the open ocean has about solids per litre, a salinity of 35 ‰. The Mediterranean Sea is slightly higher at 38 ‰, while the salinity of the northern Red Sea can reach 41‰. In contrast, some landlocked hypersaline lakes have a much higher salinity, for example the Dead Sea has dissolved solids per litre (300 ‰).