essential amino acid: Meaning and Definition of

essen'tial ami'no ac'id

Pronunciation: [key]
— Biochem. Biochem.
  1. any amino acid that is required by an animal for growth but that cannot be synthesized by the animal's cells and must be supplied in the diet.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.