Definition

1. Noun:

   • A chemical substance: Any of a large class of chemical substances, typically water-soluble, that have a sour taste, turn blue litmus paper red, and react with bases and some metals to form salts.
   • A specific psychoactive drug: (Slang) The street name for the hallucinogenic drug lysergic acid diethylamide (LSD).

2. Adjective:

   • Having a sour taste: Sharp, tart, or sour to the taste, like vinegar or lemon juice.
   • Sharp or biting in tone or manner: Harsh, sharp, bitter, or critical in speech, expression, or wit.

Examples of Usage

• Noun:

  • Vinegar contains acetic acid.
  • The scientist handled the acid with great care in the laboratory.
  • (Slang) He had a bad trip after taking acid.

• Adjective:

  • The fruit had a pleasantly acid flavor.
  • She made an acid remark about his performance, leaving him speechless.

Advanced Usage

• "Acid test": A decisive or critical test that proves the value or quality of something.

  • The new software's ability to handle massive data loads was the acid test for the development team.

• "Acid tongue": A tendency to speak in a sharp, critical, or sarcastic manner.

  • He was known for his acid tongue during political debates.

Variants and Related Words

• Acidic (adj): Having the properties of an acid; sour-tasting or sharp in manner.

  • The soil in this region is too acidic for those plants.
  • His acidic sense of humor wasn't appreciated by everyone.

• Acidity (n): The level of acid in a substance; sourness.

  • The acidity of the wine balanced its sweetness perfectly.

• Acidify (v): To make or become acid.

  • Industrial pollution can acidify rainwater.

Synonyms

• Noun (Chemical): Corrosive, etchant.
• Adjective (Taste): Sour, tart, sharp, vinegary.
• Adjective (Manner): Acerbic, caustic, biting, vitriolic, sarcastic.

Related Phrases

• Acid rain: Rain made acidic by atmospheric pollution, harmful to the environment.

  • The effects of acid rain on the forest were devastating.

• Amino acid: Organic compounds that are the building blocks of proteins.

  • Proteins are made up of chains of amino acids.

Related Idioms

• Put the acid on (someone): (Australian/NZ informal) To pressure someone strongly; to try to obtain something from someone by forceful persuasion.
  • He really put the acid on me to lend him the money.

Adjective

1. having the characteristics of an acid
   • an acid reaction
2. being sour to the taste
3. 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

Noun

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