noun
: a chronic progressive disease of the central nervous system marked by patchy demyelination and hardening of nerve tissue and associated with varied motor and psychic changes depending upon the location of the lesions
noun
: a chronic progressive disease of the central nervous system marked by patchy demyelination and hardening of nerve tissue and associated with varied motor and psychic changes depending upon the location of the lesions
Webster's New International English Dictionary. Новый международный словарь английского языка Webster. 2012