1. (常用于化妆品或美容手术中，使皮肤显得年轻的)胶原蛋白
Collagen is a protein that is found in the bodies of people and animals. It is often used as an ingredient in cosmetics or is injected into the face in cosmetic surgery, in order to make the skin look younger.

1. a fibrous scleroprotein in bone and cartilage and tendon and other connective tissue
yields gelatin on boiling