H2O

(āch`tŌ`ō´)

n.

1.

The chemical formula for water.

Thesaurus

Noun

1.

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 solvent water tear, teardrop - a drop of the clear salty saline solution secreted by the lacrimal glands; "his story brought tears to her eyes" perspiration, sudor, sweat - salty fluid secreted by sweat glands; "sweat poured off his brow" tap water - water directly from the spigot 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" flake, snowflake - a crystal of snow diamond dust, frost mist, frost snow, ice crystal, ice needle, poudrin, snow mist - small crystals of ice binary compound - chemical compound composed of only two elements 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, O, oxygen - 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 bath water - water used for a bath dishwater - water in which dishes and cooking utensils are washed distilled water - water that has been purified by distillation holy water - water that has been blessed by a priest for use in symbolic purification ground water, spring water, well water - underground water that is held in the soil and in pervious rocks hard water - water that contains mineral 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 - fluid matter having no fixed shape but a fixed volume meltwater - melted snow or ice brine, saltwater, seawater - water containing salts; "the water in the ocean is all saltwater" fresh water, freshwater - water that is not salty slush - partially melted snow soft water - water that is not hard (does not contain mineral salts that interfere with the formation of lather with soap) bilge, bilge water - water accumulated in the bilge of a ship water of crystallisation, water of crystallization, water of hydration - the water present in hydrated compounds