deteriorate  /dɪˈtɪriəˌreɪt/  verb

1 [no object] : to become worse as time passes

  • The weather gradually deteriorated as the day went on.
  • Her health continues to deteriorate.
  • efforts to save a deteriorating rain forest
  • The disagreement deteriorated into a fight.

2 [+ object] : to make something worse

  • Exposure to rain and sun will gradually deteriorate the paint.

— deteriorated adjective

  • deteriorated building
  • a badly deteriorated part of the city