acetic acid

noun

ace·​tic acid ə-ˈsē-tik- 

: a colorless pungent liquid acid C₂H₄O₂ that is the chief acid of vinegar and that is used especially in synthesis (as of plastics)

Examples of acetic acid in a Sentence

Recent Examples on the Web

Those bacteria transform the acetic acid into protein that can then be used for animal feed. —Paul Smaglik, Discover Magazine, 20 Mar. 2025

These include wild yeast (almost always Saccharomyces cerevisiae), lactic acid and acetic acid bacteria. —Michael Allen, JSTOR Daily, 20 Mar. 2025

Although scientists don't fully understand the mechanics, the acetic acid in apple cider vinegar can help to lower blood sugar. —Yvelette Stines, Verywell Health, 18 Mar. 2025

Proponents also claim that the acetic acid found in apple cider vinegar prevents fat from storing in your body and improves your metabolism. —Elizabeth Barnes, Verywell Health, 24 Feb. 2025

Word History

Etymology

acetic borrowed from French acétique, from Latin acētum "sour wine, vinegar" (noun derivative from *acētus, verbal adjective of acēre "to be sour," going back to Indo-European h₂eḱ-eh₁- "to be sharp") + French -ique -ic entry 1 — more at edge entry 1

First Known Use

1788, in the meaning defined above

Rhymes for acetic acid

• antacid
• placid

Kids Definition

acetic acid

noun

: a colorless strong-smelling liquid acid that gives the sour taste to vinegar and that is used especially in making chemical compounds (as plastics)

Medical Definition

acetic acid

noun

: a colorless pungent liquid acid C₂H₄O₂ that is the chief acid of vinegar and that is used especially in synthesis (as of plastics) and occasionally in medicine as an astringent and styptic