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/ˈæsɪd/
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/ˈæsɪd/
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/ˈæsɪd/
🇬🇧
/ˈæsɪd/
Plural
acids
Acid is a substance that tastes sour, turns blue litmus paper red, reacts with bases to form salt and water, and donates hydrogen ions (H⁺) in solution — think vinegar, lemon juice, or battery fluid. In everyday language, it can also describe something sharply critical or harsh, like 'an acid remark'.
Lemon juice contains citric acid, which gives it its tangy flavor.
Sulfuric acid is used in car batteries and industrial manufacturing.
Acid rain damages forests and erodes historic stone buildings.
Her critique was delivered with such acid wit that no one dared respond.
The soil's acidity increased after repeated applications of nitrogen fertilizer.
acid
Comes from the Latin noun 'acidus' (feminine 'acida', neuter 'acidum'), meaning 'sour' or 'sharp-tasting', derived from the verb 'acere' ('to be sour'). This root conveys the core chemical and sensory concept of sourness, sharpness, and corrosiveness. Examples include acid, acidic, acidify, acrid, acetate, and acetic.