What is "acid"

Acid \Ac"id\, a. [L. acidus sour, fr. the root ak to be sharp: cf. F. acide. Cf. Acute.]

1. Sour, sharp, or biting to the taste; tart; having the taste of vinegar: as, acid fruits or liquors. Also fig.: Sour-tempered.

   He was stern and his face as acid as ever.
   --A. Trollope.

2. Of or pertaining to an acid; as, acid reaction.

Acid \Ac"id\, n.

1. A sour substance.

2. (Chem.) One of a class of compounds, generally but not always distinguished by their sour taste, solubility in water, and reddening of vegetable blue or violet colors. They are also characterized by the power of destroying the distinctive properties of alkalies or bases, combining with them to form salts, at the same time losing their own peculiar properties. They all contain hydrogen, united with a more negative element or radical, either alone, or more generally with oxygen, and take their names from this negative element or radical. Those which contain no oxygen are sometimes called hydracids in distinction from the others which are called oxygen acids or oxacids.

   Note: In certain cases, sulphur, selenium, or tellurium may take the place of oxygen, and the corresponding compounds are called respectively sulphur acids or sulphacids, selenium acids, or tellurium acids. When the hydrogen of an acid is replaced by a positive element or radical, a salt is formed, and hence acids are sometimes named as salts of hydrogen; as hydrogen nitrate for nitric acid, hydrogen sulphate for sulphuric acid, etc. In the old chemistry the name acid was applied to the oxides of the negative or nonmetallic elements, now sometimes called anhydrides.

1620s, "of the taste of vinegar," from French acide (16c.) or directly from Latin acidus "sour, sharp," adjective of state from acere "to be sour," from PIE root *ak- "sharp, pointed" (see acrid). Figurative use from 1775; applied to intense colors from 1916. Acid test is American English, 1892, from the frontier days, when gold was distinguished from similar metals by application of nitric acid. Acid rain is first recorded 1859 in reference to England.

1690s, from acid (adj.). Slang meaning "LSD-25" first recorded 1966 (see LSD).\n\nWhen I was on acid I would see things that looked like beams of light, and I would hear things that sounded an awful lot like car horns.

[Mitch Hedberg, 1968-2005, U.S. stand-up comic]

n. (context databases English) (acronym of atomicity, consistency, isolation, and durability English), a set of properties that guarantee database transactions are processed reliably

1. adj. harsh or corrosive in tone; "an acerbic tone piercing otherwise flowery prose"; "a barrage of acid comments"; "her acrid remarks make her many enemies"; "bitter words"; "blistering criticism"; "caustic jokes about political assassination, talk-show hosts and medical ethics"; "a sulfurous denunciation" [syn: acerb, acerbic, acrid, bitter, blistering, caustic, sulfurous, sulphurous, venomous, virulent, vitriolic]

2. containing acid; "an acid taste"

1. n. 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

2. street name for lysergic acid diethylamide [syn: back breaker, battery-acid, dose, dot, Elvis, loony toons, Lucy in the sky with diamonds, pane, superman, window pane, Zen]

In computer science, ACID ( Atomicity, Consistency, Isolation, Durability) is a set of properties of database transactions. In the context of databases, a single logical operation on the data is called a transaction. For example, a transfer of funds from one bank account to another, even involving multiple changes such as debiting one account and crediting another, is a single transaction.

Jim Gray defined these properties of a reliable transaction system in the late 1970s and developed technologies to achieve them automatically.

In 1983, Andreas Reuter and Theo Härder coined the acronym ACID to describe them.

An acid is any chemical compound that, when dissolved in water, gives a solution with a pH less than 7.0.

Acid or ACID may also refer to:

Acid was a Japanese rock band originally created by Hideki after Siam Shade disbanded.

Acid (often written ACID; , ) is a Burmese hip hop group often credited with releasing Burma's first hip hop album, Beginning, in 2000. Two of the group's founders were later imprisoned for the group's allegedly pro-democracy lyrics.

Acid is a computer virus which infects .COM and .EXE files including [[command.com]]. Each time an infected file is executed, Acid infects all of the .EXE files in the current directory. Later, if an infected file is executed, it infects the .COM files in the current directory. Programs infected with Acid will have had the first 792 bytes of the host program overwritten with Acid's own code. There will be no file length increase unless the original host program was smaller than 792 bytes, in which case it will become 792 bytes in length. The program's date and time in the DOS disk directory listing will not be altered.

The following text strings are found in infected files:

• "*.EXE *.COM .."
• "Program too big to fit in memory"
• "Acid Virus"
• "Legalize ACiD and Pot"
• "By: Copyfright Corp-$MZU"