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

Additionally, there's some evidence that acetic acid—which is found in vinegar, including apple cider vinegar—can stimulate a hormone that promotes fullness, but more studies are needed on this, says DeRobertis. —Kirsten Nunez, Martha Stewart, 21 Jan. 2026

Kills Bacteria During the fermentation process, a substance called acetic acid is produced in kombucha. —Julie Marks, Verywell Health, 14 Jan. 2026

Kombucha contains acetic acid, which may help limit sharp rises in blood sugar after meals. —Lindsey Desoto, Health, 12 Jan. 2026

Though some of these preservatives were not associated with cancer incidence, others were, including potassium sorbate, potassium metabisulfite, sodium nitrite, potassium nitrate and acetic acid. —Sara Moniuszko, USA Today, 8 Jan. 2026

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