The Collaborative International Dictionary of English v.0.48:

cardiosclerosis \car"di*o*scle*ro"sis\, n. [NL., fr. Gr. kardi`a
   heart + sclerosis.]
   Induration of the heart, caused by development of fibrous
   tissue in the cardiac muscle. [Obsolescent]
   [Webster 1913 Suppl. +PJC]