noun
protein
PROH-tee-ihn
noun
1
A large biological molecule made of chains of amino acids, essential to the structure and function of living cells.
"Muscles are largely built from protein."
"The enzyme is a protein that speeds up digestion."
2
Food that is a major source of this nutrient, especially meat, fish, eggs, or legumes.
"Try to include some protein with every meal."
How to Use Protein
Learner’s notesIn plain EnglishOne of the body's essential building blocks, found in foods like meat, eggs, and beans, and in every living cell.
Common pairings
protein source
high in protein
protein shake
Word Forms
proteins plural
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Etymology
Coined from Greek prōteîos ("primary, of first importance") by chemist Jöns Jacob Berzelius, suggesting these molecules are fundamental to life.