Deteriorate \De*te"ri*o*rate\, v. t. [imp. & p. p.
{Deteriorated}; p. pr. & vb. n. {Deteriorating}.] [L.
deterioratus, p. p. of deteriorate to deteriorate, fr.
deterior worse, prob. a comparative fr. de down, away.]
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.