oxalic acid

noun

ox·​al·​ic acid (ˌ)äk-ˈsa-lik- How to pronounce oxalic acid (audio)
: a poisonous strong acid (COOH)2 or H2C2O4 that occurs in various plants (such as spinach) as oxalates and is used especially as a bleaching or cleaning agent and as a chemical intermediate

Examples of oxalic 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.
While the leaves contain the toxin oxalic acid, the stalks are safe to eat both raw and cooked. — Bestreviews, Mercury News, 5 June 2026 Research had identified oxalic acid as a key factor in the blight’s virulence. — ArsTechnica, 12 Feb. 2026 Boiling tomatoes may reduce oxalic acid levels, which can help people prone to kidney stones, while increasing lycopene content. — Cristina Mutchler, Verywell Health, 10 June 2026 In the digestive system, oxalic acid can bind to minerals like calcium and inhibit their absorption. — Roxana Ehsani, Health, 21 May 2025 See All Example Sentences for oxalic acid

Word History

Etymology

French (acide) oxalique, from Latin oxalis

First Known Use

1788, in the meaning defined above

Time Traveler
The first known use of oxalic acid was in 1788

Rhymes for oxalic acid

See All Rhymes for oxalic acid

Browse Nearby Words

oxaldehyde
oxalic acid
Oxalidaceae
See all Nearby Words

Cite this Entry

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

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Medical Definition

oxalic acid

noun
ox·​al·​ic acid (ˌ)äk-ˌsal-ik- How to pronounce oxalic acid (audio)
: a poisonous strong acid (COOH)2 or H2C2O4 that occurs in various plants as oxalates and is used especially as a bleaching or cleaning agent and as a chemical intermediate

More from Merriam-Webster on oxalic acid

Britannica.com: Encyclopedia article about oxalic acid

Last Updated: - Updated example sentences
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