amino acid

noun

: an amphoteric organic acid containing the amino group NH2
especially : any of the various amino acids having the amino group in the alpha position that are the chief components of proteins and are synthesized by living cells or are obtained as essential components of the diet

Examples of amino acid in a Sentence

Recent Examples on the Web
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In addition, dietary tryptophan – an amino acid found in foods such as poultry, eggs, tofu and seeds – is metabolized into compounds that activate the aryl hydrocarbon receptor, further boosting Treg cell activity and protecting against gut inflammation. Mitzi Nagarkatti, The Conversation, 10 Oct. 2025 Some amino acids are very close in structure to glucose and can be easily converted to glucose in the liver. Bryant Stamford, Louisville Courier Journal, 9 Oct. 2025 Infused with vitamin B12, vitamin C, magnesium and amino acids, this preservative-free formula is gentle on sensitive eyes and helps keep them comfortable and protected. Adam Mills, MSNBC Newsweek, 8 Oct. 2025 This amino acid is thought to support relaxation and brain health. Team Verywell Health, Verywell Health, 6 Oct. 2025 See All Example Sentences for amino acid

Word History

First Known Use

1897, in the meaning defined above

Time Traveler
The first known use of amino acid was in 1897

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Cite this Entry

“Amino acid.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/amino%20acid. Accessed 14 Oct. 2025.

Kids Definition

amino acid

noun
ami·​no acid
ə-ˈmē-nō-
: any of numerous acids that include some which are the building blocks of proteins and are made by living cells from simpler compounds or are obtained in the diet

Medical Definition

amino acid

noun
: an amphoteric organic acid containing the amino group NH2
especially : alpha-amino acid

More from Merriam-Webster on amino acid

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