n., pl., -ses (-sēz).
- A thickening or hardening of a body part, as of an artery, especially from excessive formation of fibrous interstitial tissue.
- A disease characterized by this thickening or hardening.
- Botany. The hardening of cells by the formation of a secondary wall and the deposition of lignin.
[Middle English sclirosis, from Medieval Latin sclīrōsis, from Greek sklērōsis, hardening, from sklēroun, to harden. See scleroma.]





