scler(o)-

Hard; hardening.

Greek sklēros, hard.

Sclerosis is abnormal hardening of body tissue, as in multiple sclerosis, a disease involving damage to the sheaths of nerve cells; several compound terms exist, an example being arteriosclerosis, thickening and hardening of the walls of the arteries. A scleroderma (Greek derma, skin) is a chronic hardening and contraction of the skin and connective tissue; the sclera is the hard outer layer of the eyeball; sclerotherapy is treatment of varicose blood vessels using hardening chemicals.

A scleroprotein is an insoluble structural protein such as keratin, collagen, or elastin; a sclerophyll (Greek phullon, leaf) is a woody plant with evergreen leaves that are tough and thick in order to reduce water loss; sclerenchyma (Greek enkhuma, infusion) is supporting or protective tissue composed of hardened cells, as in the skeletons of corals.