sclerosis

noun, plural scle·ro·ses [skli-roh-seez] /sklɪˈroʊ siz/.

1. Pathology. a hardening or induration of a tissue or part, or an increase of connective tissue or the like at the expense of more active tissue.
2. Botany. a hardening of a tissue or cell wall by thickening or lignification.

noun plural -ses (-siːz)

1. pathol a hardening or thickening of organs, tissues, or vessels from chronic inflammation, abnormal growth of fibrous tissue, or degeneration of the myelin sheath of nerve fibres, or (esp on the inner walls of arteries) deposition of fatty plaquesCompare arteriosclerosis, atherosclerosis, multiple sclerosis
2. the hardening of a plant cell wall or tissue by the deposition of lignin
3. a debilitating lack of progress or innovation within an institution or organization

n.“morbid hardening of the tissue,” late 14c., from Medieval Latin sclirosis “a hardness, hard tumor,” from Greek sklerosis “hardening,” from skleros “hard” (see sclero-). Figurative use by 1954. n. pl. scle•ro•ses (-sēz)

1. The hardening of a tissue or part due to chronic inflammation.
2. A thickening or hardening of a body part or system especially from excessive formation of fibrous interstitial or glial tissue.
3. Any of various diseases characterized by thickening or hardening, such as arteriosclerosis.