What does Boxing Day have to do with boxing?
sclerosis scle·ro·sis (sklə-rō'sĭs)
n. pl. scle·ro·ses (-sēz)
The hardening of a tissue or part due to chronic inflammation.
A thickening or hardening of a body part or system especially from excessive formation of fibrous interstitial or glial tissue.
Any of various diseases characterized by thickening or hardening, such as arteriosclerosis.