essential amino acid

noun

: any of various amino acids that are required for normal health and growth in many vertebrates, are either not manufactured in the body or manufactured in insufficient quantities, are usually supplied by dietary protein, and include histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine compare nonessential amino acid

Examples of essential amino acid in a Sentence

Recent Examples on the Web

The protein in quinoa contains all the essential amino acids needed for healthy muscles and bones. —Bethany Thayer, Freep.com, 12 July 2025

Regardless, this cheese is a complete milk protein and has a particularly high concentration of lysine, an essential amino acid necessary for building muscles, as well as calcium to support strong bones. —Philipp Wehsack, Vogue, 11 July 2025

Tryptophan is an essential amino acid that your body doesn’t produce, so it must be obtained from food. —Merve Ceylan, Health, 12 May 2025

Eggs themselves are not a source of collagen—but the egg white specifically contains proline and glycine, two essential amino acids for proper collagen production. —Alessandra Signorelli, Vogue, 1 July 2025

Word History

First Known Use

1911, in the meaning defined above

Rhymes for essential amino acid

• antacid
• placid

Kids Definition

essential amino acid

noun

: an amino acid that is necessary for proper growth of the animal body and that cannot be made by the body in sufficient amounts but must be obtained from food containing proteins

Medical Definition

essential amino acid

noun

: any of various alpha-amino acids that are required for normal health and growth, are either not manufactured in the body or manufactured in insufficient quantities, are usually supplied by dietary protein, and in humans include histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine