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

China has also worked to dominate the production of the vitamins and amino acids that are essential to animal feed. — Caitlin Welsh, Foreign Affairs, 11 Aug. 2026

By making pores appear smoother and diffusing the light in a particular way, the amino acid powders give a filter-like effect while letting the natural skin shine through. — Kiana Murden, Vogue, 11 Aug. 2026

Peptides, the short chains of amino acids that help regulate biological functions, have become the latest obsession in health, fitness and longevity. — Robert Pearl, Forbes.com, 10 Aug. 2026

Each scoop delivers 10 grams of low molecular weight Type 3 and 1 collagen peptides with 18 amino acids including glycine, proline and hydroxyproline. — Lauren Jarvis-Gibson, Fort Worth Star-Telegram, 10 Aug. 2026

Word History

First Known Use

1897, in the meaning defined above

Rhymes for amino acid

• antacid
• placid

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