formic acid

noun

for·​mic acid ˈfȯr-mik- How to pronounce formic acid (audio)
: a colorless pungent fuming vesicant liquid acid CH2O2 found especially in ants and in many plants and used chiefly in dyeing and finishing textiles

Examples of formic acid in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
However, these ants are well known for their use of defensive compounds (formic acid), which are distasteful to most species. — Scott Travers, Forbes.com, 4 Apr. 2026 In testing, the setup produced a pure aqueous formic acid solution under real sunlight, even as the light intensity changed. — New Atlas, 21 June 2026 For every molecule of pigment generated, the cell also produced one molecule of formic acid. — Ashley MacKin Solomon, San Diego Union-Tribune, 19 Nov. 2025 Harvester ants are aggressive, well-armored and loaded with defensive chemicals, including formic acid. — Ryan Brennan, Kansas City Star, 13 Apr. 2026 See All Example Sentences for formic acid

Word History

Etymology

irregular from Latin formica ant — more at pismire

First Known Use

1790, in the meaning defined above

Time Traveler
The first known use of formic acid was in 1790

Rhymes for formic acid

See All Rhymes for formic acid

Browse Nearby Words

Formica
formic acid
formic aldehyde
See all Nearby Words

Cite this Entry

“Formic acid.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/formic%20acid. Accessed 7 Jul. 2026.

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Kids Definition

formic acid

noun
for·​mic acid ˌfȯr-mik- How to pronounce formic acid (audio)
: a colorless strong-smelling acid that irritates the skin, is found in insects (as ants) and in many plants, and is used chiefly in dyeing and finishing woven fabrics

Medical Definition

formic acid

noun
: a colorless pungent fuming vesicant liquid acid CH2O2 found especially in ants and in many plants and used chiefly in dyeing and finishing textiles

More from Merriam-Webster on formic acid

Britannica.com: Encyclopedia article about formic acid

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