water containing salts; "the water in the ocean is all saltwater"
Water that comes from the ocean and is very salty.
Water containing salt and other minerals; ocean water. Full strength seawater contains 35 parts of salt for each 1000 parts water (salinity = 35 ppt).
Water which has a chloride concentration equal to or greater than 19,000 mg/l.
The water of the seas, distinguished from freshwater by its appreciable salinity. The distinction in usage of saltwater and seawater is not very sharply drawn. Commonly, seawater is used as the antithesis of specific types of freshwater, as river water, lake water, rainwater, etc., whereas saltwater is merely the antithesis of freshwater in general.
Seawater is water from a sea or ocean. On average, seawater in the world's oceans has a salinity of ~3.5%, or 35 parts per thousand. This means that every 1 kg of seawater has approximately 35 grams of salts (mostly, but not entirely, sodium chloride) dissolved in it.