ETYM Latin acidus sour, from the root ak to be sharp: cf. French acide. Related to Acute.
(Chemistry) Containing acid.
1. Harsh or corrosive in tone
2. Being sour to the taste
3. Having the characteristics of an acid

Množina: acids

Compound that, in solution in an ionizing solvent (usually water), gives rise to hydrogen ions (H+ or protons). In modern chemistry, acids are defined as substances that are proton donors and accept electrons to form ionic bonds. Acids react with bases to form salts, and they act as solvents. Strong acids are corrosive; dilute acids have a sour or sharp taste, although in some organic acids this may be partially masked by other flavor characteristics.
Acids can be detected by using colored indicators such as litmus and methyl orange. The strength of an acid is measured by its hydrogen-ion concentration, indicated by the pH value. Acids are classified as monobasic, dibasic, tribasic, and so forth, according to the number of hydrogen atoms, replaceable by bases, in a molecule. The first known acid was vinegar (ethanoic or acetic acid). Inorganic acids include boric, carbonic, hydrochloric, hydrofluoric, nitric, phosphoric, and sulfuric. Organic acids include acetic, benzoic, citric, formic, lactic, oxalic, and salicylic, as well as complex substances such as nucleic acids and amino acids.
Any of various water-soluble compounds having a sour taste and capable of turning litmus red and reacting with a base to form a salt.

Množina: acid criticisms

Singular of acid drops is acid drop.

Množina: acid houses

Type of house music. The derivation of the term is disputed but may be from “acid burning”, Chicago slang for digital sampling, a recording technique much featured in acid house. acid-house.

Množina: acid precipitations

Precipitation (as rain or snow) having increased acidity caused by environmental factors (as atmospheric pollutants).
Rain containing acids that form in the atmosphere when industrial gas emissions (especially sulphur dioxide and nitrogen oxides) combine with water

Množina: acid rains

Rain containing acids that form in the atmosphere when industrial gas emissions combine with water; SYN. acid precipitation.
Acidic precipitation thought to be caused principally by the release into the atmosphere of sulfur dioxide (SO2) and oxides of nitrogen. Sulfur dioxide is formed by the burning of fossil fuels, such as coal, that contain high quantities of sulfur; nitrogen oxides are contributed from various industrial activities and from automobile exhaust fumes.
Acid deposition occurs not only as wet precipitation (mist, snow, or rain), but also comes out of the atmosphere as dry particles or is absorbed directly by lakes, plants, and masonry as gases. Acidic gases can travel over 500 km a day so acid rain can be considered an example of transboundary pollution.
Acid rain is linked with damage to and the death of forests and lake organisms in Scandinavia, Europe, and eastern North America. It also results in damage to buildings and statues. US and European power stations that burn fossil fuels release some 8 g/0.3 oz of sulfur dioxide and 3 g/0.1 oz of nitrogen oxides per kilowatt-hour. According to the UK Department of the Environment figures, emissions of sulfur dioxide from power stations would have to be decreased by 81% in order to arrest damage.
The main effect of acid rain is to damage the chemical balance of soil, causing leaching of important minerals including magnesium and aluminum. Plants living in such soils, particularly conifers, suffer from mineral loss and become more prone to infection. The minerals from the soil pass into lakes and rivers, disturbing aquatic life, for instance, by damaging the gills of young fish. Lakes and rivers suffer more direct damage as well because they become acidified by rainfall draining directly from their catchment.

(Histology) Not easily decolorized by acid solutions; pertains to micro-organisms (especially the tubercle bacillus that causes tuberculosis).