acid

ac-id · noun

imported

Definitions

noun

  1. 1.

    (Chemistry) A chemical substance that neutralizes alkalis, dissolves some metals, and turns litmus red.

  2. 2.

    A sour-tasting substance.

  3. 3.

    (Slang) The drug LSD.

  4. 4.

    Containing acid; having a pH less than 7.

  5. 5.

    Sharp-tasting; sour.

  6. 6.

    Sharp or critical in tone.

Forms

plural: acids

Phrases & expressions

  • •
    acid test — A severe or conclusive test.
  • •
    acid rain — Rain polluted by atmospheric acids.
  • •
    acid reflux — Stomach acid backing up into the esophagus.
  • •
    amino acid — Building blocks of proteins.
  • •
    battery acid — Sulfuric acid used in batteries.

Related words

Antonyms: alkali, base
See also: acidic, acidity, base, sour
Synonyms: corrosive, sour substance

Etymology

From Latin acidus ("sour"), from acere ("to be sour"), related to acer ("sharp").