H2O - binary compound that occurs at room temperature as a clear colorless odorless tasteless liquid; freezes into ice below 0 degrees centigrade and boils above 100 degrees centigrade; widely used as a solventtear, teardrop - a drop of the clear salty saline solution secreted by the lacrimal glands; "his story brought tears to her eyes" body of water, water - the part of the earth's surface covered with water (such as a river or lake or ocean); "they invaded our territorial waters"; "they were sitting by the water's edge" atomic number 1, H, hydrogen - a nonmetallic univalent element that is normally a colorless and odorless highly flammable diatomic gas; the simplest and lightest and most abundant element in the universe atomic number 8, oxygen, O - a nonmetallic bivalent element that is normally a colorless odorless tasteless nonflammable diatomic gas; constitutes 21 percent of the atmosphere by volume; the most abundant element in the earth's crust dishwater - water in which dishes and cooking utensils are washed holy water - water that has been blessed by a priest for use in symbolic purification hard water - water that contains salts (as calcium and magnesium ions) that limit the formation of lather with soap ice, water ice - water frozen in the solid state; "Americans like ice in their drinks" limewater - solution of calcium hydroxide in water used as an antacid liquid - a substance in the fluid state of matter having no fixed shape but a fixed volume slush - partially melted snow soft water - water that is not hard (does not contain salts that interfere with the formation of lather with soap) |