Noun | 1. | collagen - a fibrous scleroprotein in bone and cartilage and tendon and other connective tissue; yields gelatin on boiling connective tissue - tissue of mesodermal origin consisting of e.g. collagen fibroblasts and fatty cells; supports organs and fills spaces between them and forms tendons and ligaments albuminoid, scleroprotein - a simple protein found in horny and cartilaginous tissues and in the lens of the eye |