1. a complex molecule made of amino acids that is essential for the structure and function of living organisms
Usage: biology; chemistry
2. food that contains a high amount of protein, especially meat, fish, eggs, or beans
Usage: nutrition

Examples

• Muscles are made primarily of protein.
• The body needs protein to repair damaged tissue.
• Chicken and fish are excellent sources of protein.
• Vegetarians can get protein from beans and nuts.
• The scientist studied how proteins fold in the cell.
• Athletes often eat extra protein to build muscle.
• This protein shake contains 25 grams of whey protein.