Chemistry. a compound usually having a sour taste and capable of neutralizing alkalis and reddening blue litmus paper, containing hydrogen that can be replaced by a metal or an electropositive group to form a salt, or containing an atom that can accept a pair of electrons from a base. Acids are proton donors that yield hydronium ions in water solution, or electron-pair acceptors that combine with electron-pair donors or bases.
2.
a substance with a sour taste.
3.
something, as a remark or piece of writing, that is sharp, sour, or ill-natured: His criticism was pure acid.
belonging or pertaining to acids or the anhydrides of acids.
b.
having only a part of the hydrogen of an acid replaced by a metal or its equivalent: an acid phosphate.
c.
having a pH value of less than 7. Compare alkaline(def. 4).
6.
sharp or biting to the taste; tasting like vinegar; sour: acid fruits.
7.
sharp, biting, or ill-natured in mood, manner, etc.: an acid remark; an acid wit.
8.
Geology. containing much silica.
9.
Metallurgy. noting, pertaining to, or made by a process in which the lining of the furnace, or the slag that is present, functions as an acid in high-temperature reactions in taking electrons from oxide ions: usually a siliceous material, as sand or ganister. Compare basic(def. 3).
—Idiom
10.
put on the acid, AustralianSlang. to importune someone, as for money, sexual favors, or confidential information.
[Origin: 1620–30; < L acidus sour, akin to ācer sharp, acétum vinegar, acescent, acicula]
—Related forms
ac·id·ly, adverb
ac·id·ness, noun
—Synonyms 7. acerbic, stinging, vitriolic, tart. Acid,astringent are terms used figuratively of wit or humor. Acid suggests a sharp, biting, or ill-natured quality: an acid joke about an opponent. Astringent connotes severity but usually also a bracing quality, as of something applied with curative intent: astringent criticism.
Any of a class of substances whose aqueous solutions are characterized by a sour taste, the ability to turn blue litmus red, and the ability to react with bases and certain metals to form salts.
A substance that yields hydrogen ions when dissolved in water.
A substance that can act as a proton donor.
A substance that can accept a pair of electrons to form a covalent bond.
A substance having a sour taste.
The quality of being sarcastic, bitter, or scornful: wrote with acid about her first marriage.
LSD 1Audio Help (ěl'ěs-dē') Pronunciation Key
n.
A crystalline compound, C20H25N3O, derived from lysergic acid and used as a powerful hallucinogenic drug. Also called acid.
1626, from Fr. acide, from L. acidus "sour," adj. of state from acere "to be sour," from PIE base *ak- "sharp, pointed" (see acrid). Applied to intense colors from 1916. Slang meaning "LSD-25" first recorded 1966 (see LSD); acid rock (type played by or listen to by people using LSD) is also from 1966; acid house dance music style is 1988, probably from acid in the hallucinogenic sense + house, "dance club DJ music style," probably from the Warehouse, a Chicago nightclub where the style originated. Acid test is Amer.Eng., 1892, from the frontier days, when gold was distinguished from similar metals by application of nitric acid. Acid rain is first recorded 1859 in ref. to England.
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"; "a vitriolic critique"
acidAudio Help (ās'ĭd) Pronunciation Key
Any of a class of compounds that form hydrogen ions when dissolved in water, and whose aqueous solutions react with bases and certain metals to form salts. Acids turn blue litmus paper red and have a pH of less than 7. Their aqueous solutions have a sour taste. Compare base.
A sour-tasting material (usually in a solution) that dissolves metals and other materials. Technically, a material that produces positive ions in solution. An acid is the opposite of a base and has a pH of 0 to 7. A given amount of an acid added to the same amount of a base neutralizes the base, producing water and a salt. Common vinegar, for example, is a weak solution of acetic acid.
Note: Figuratively, acid applies to anything sour or biting; for example, an “acid wit” is sharp and unpleasant.
ACIDprogramming A mnemonic for the properties a transaction should have to satisfy the Object Management GroupTransaction Service specifications. A transaction should be Atomic, its result should be Consistent, Isolated (independent of other transactions) and Durable (its effect should be permanent). The Transaction Service specifications which part of the Object Services, an adjunct to the CORBA specifications. (1997-05-15)
A*ces"cent\, a. [L. acescens, -entis, p. pr. of acescere to turn sour; inchoative of acere to be sour: cf. F. acescent. See Acid.] Turning sour; readily becoming tart or acid; slightly sour. --Faraday.
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.
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Audio Help [as-id] Pronunciation Key 
