Dictionary > English Dictionary > Definition, synonym and antonym of acid
Meaning of acid by Wiktionary Dictionary



    From French acide, from Latin acidus ( “sour, acid” ), from aceō ( “I am sour” ) .


    • IPA: /ˈæs.ɪd/, X-SAMPA: /"{s.Id/
    • Hyphenation: a‧cid


    acid ( comparative more acid, superlative most acid )

    1. Sour, sharp, or biting to the taste; tart; having the taste of vinegar .
      acid fruits or liquors
    2. ( figuratively ) Sour-tempered .
    3. Of or pertaining to an acid; acidic .
    4. ( music ) Denoting a musical genre that is a distortion ( as if hallucinogenic ) of an existing genre, as in acid house, acid jazz, acid rock .



    • acidic


    • alkaline
    • base


    acid ( plural: acids )

    1. A sour substance .
    2. ( chemistry ) Any of several classes of compound having the following properties:-
      1. Any of a class of water-soluble compounds, having sour taste, that turn blue litmus red, and react with some metals to liberate hydrogen, and with bases to form salts .
      2. Any compound that easily donates protons; a Brønsted acid
      3. Any compound that can accept a pair of electrons to form a covalent bond; a Lewis acid
    3. ( slang ) lysergic acid diethylamide


    • alkali
    • base


    • See also Wikisaurus:acid

    Derived terms

    See also

    • acerbic
    • acro-
    • pH

    See also

    • acid in Webster’s Revised Unabridged Dictionary, G. & C. Merriam, 1913


Explanation of acid by Wordnet Dictionary


    1. having the characteristics of an acid

    2. an acid reaction
    3. harsh or corrosive in tone

    4. a barrage of acid comments
    5. being sour to the taste

    1. street name for lysergic acid diethylamide

    2. 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

    Definition of acid by GCIDE Dictionary


    1. Acid 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”.

    2. Acid, 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.

      ☞ 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.