Another spelling bee word:
sclerosis
n.,
pl. 3ses 73scz#8 5ME sclirosis < ML < Gr sklcrbsis, a hardening < sklcros, hard: see SCLERA6
1 Bot. a hardening of the cell wall of a plant, usually by an increase of lignin
2 Med.
a) an abnormal hardening of body tissues or parts, esp. of the nervous system or the walls of arteries b) a disease characterized by this