deteriate

Verb

deteriorate (third-person singular simple present deteriorates, present participle deteriorating, simple past and past participle deteriorated)

1. (transitive) To make worse; to make inferior in quality or value; to impair.
   • to deteriorate the mind
2. (intransitive) To grow worse; to be impaired in quality; to degenerate.
   • During this fine run through Fife the weather had deteriorated rapidly, and as we passed Wormit and came onto the Tay Bridge heavy rain clouds were piled over the sea.1947 January and February, O. S. Nock, “"The Aberdonian" in Wartime”, in Railway Magazine, page 7