Meaning of ACID in English

I. ˈasə̇d, ˈaa- adjective

Etymology: French or Latin; French acide, from Latin acidus, from acēre to be sour — more at acute


a. : sharp or biting to the taste

acid lemons

: sour , tart

the acid juice of unripe grapes

an acid apple

b. : sharp, biting, or sour in manner, disposition, or nature

his acid way of dealing with people

an acid misanthrope

: prone to antagonize, wound, or humiliate : repellently disagreeable : unpleasant , offensive

an acid individual, unable to get along with anyone

: cutting , caustic

acid remarks

acid gibes

: corrosive

acid hatred

c. : sharply clear, discerning, pointed, and usually more or less mocking or sarcastic

acid criticism

an acid analysis of the situation

acid wit

: penetrating , trenchant , incisive : quick in perception

his cold and acid intelligence

: shrewd , acute

d. : severe and uncompromising : harsh , rigid , inflexible , unyielding

a censorious and acid attitude toward freedom of thought

e. : piercingly intense

the acid radiance of the bright sunlight

and often jarring

acid splashes of brilliant yellows

or shrill

a singing voice that unfortunately becomes sometimes acid in the upper register

2. : of, relating to, or having the characteristics of an acid: as

a. : having an acid reaction : having a pH of less than 7

acid soil

a slightly acid solution


(1) : derived from an acid

acid iodide

(2) of salts and esters : derived by partial exchange of replaceable hydrogen

acid potassium sulfate KHSO 4

c. : containing or involving the use of an acid

acid bath

acid sludge

acid hydrolysis

d. : characterized by or resulting from an abnormally high concentration of acid

acid condition of the stomach

acid indigestion

— not used technically

e. : relating to or made by an acid process

acid steel

3. : rich in silica : persilicic

acid rocks

— opposed to basic

Synonyms: see sour

II. noun

( -s )

Etymology: New Latin acidum, from Latin, neuter of acidus, adjective

1. : a sour substance


a. : a compound (as hydrochloric acid, sulfuric acid, or benzoic acid) capable of reacting with a base to form a salt, its aqueous solutions if it is water-soluble tasting sour, reddening litmus, and evolving hydrogen on reaction with certain metals (as iron, zinc, tin) : a compound (HX) containing hydrogen that in aqueous solution yields hydrogen ion (H + ) hydrated to hydronium ion (as H 3 O + ), together with the anion (X - ), the degree of ionization in dilute solutions of strong acids (as nitric, hydrochloric, or trichloroacetic acid) being virtually complete, that of weak acids (as acetic or benzoic acid) being possibly one percent, and that of very weak acids (as hydrocyanic or boric acid) being much less than one percent — compare hydrogen-ion concentration , ph

b. according to the Brønsted-Lowry system : a hydrogen-containing molecule (as nitric acid) or ion (as hydronium, ammonium, or bicarbonate) that can give up a proton to a base : a proton donor

hydrogen chloride is the conjugate acid of the chloride ion

c. according to the G.N.Lewis system : a substance capable of accepting from a base an unshared pair of electrons which then form a covalent chemical bond, many compounds (as boron fluoride, sulfur trioxide, or carbon dioxide) as well as protons and other positive ions being thus included in this class — called also Lewis acid

3. : dilute sulfuric acid used in storage batteries

4. : something sharp, biting, sour, or corrosive

a social satire dripping with acid

destroying freedom with the acid of narrow-mindedness

III. noun

: lsd

Webster's New International English Dictionary.      Новый международный словарь английского языка Webster.