Definition of acid noun from the Oxford Advanced Learner's Dictionary



    BrE BrE//ˈæsɪd//
    ; NAmE NAmE//ˈæsɪd//
    jump to other results
  1. 1   [uncountable, countable] (chemistry) a chemical, usually a liquid, that contains hydrogen and has a pH of less than seven. The hydrogen can be replaced by a metal to form a salt. Acids are usually sour and can often burn holes in or damage things they touch. compare alkali Wordfinderacid, catalyst, chemistry, compound, formula, molecule, pH, react, solution, valency see also acetic acid, amino acid, ascorbic acid, citric acid, hydrochloric acid, lactic acid, nitric acid, nucleic acid, sulphuric acid
  2. 2 [uncountable] (slang) = LSD
  3. Word Originearly 17th cent. (in the sense ‘sour-tasting’): from Latin acidus, from acere ‘be sour’.Extra examples He described the music as ‘Brahms on acid’. Stomach acids can break down the poison. The acid burned a hole in her coat. They smoke joints and drop acid. You will need a special chemical to neutralize the acid. fish that are rich in omega-3 fatty acids smoking joints and dropping acid the increasingly painful build-up of lactic acid in your muscles
See the Oxford Advanced American Dictionary entry: acid