What does "deteriorate" mean?

Deteriorate: To make worse; to make inferior in quality or value; to impair; as, to deteriorate the mind. Whately. The art of war . . . was greatly deteriorated. Southey.

Additional senses

  1. 2.To grow worse; to be impaired in quality; to degenerate. Under such conditions, the mind rapidly deteriorates. Goldsmith.

Sources