de·te·ri·o·rate 
/dɪˈtirijəˌreɪt/ verb
de·te·ri·o·rates; de·te·ri·o·rat·ed; de·te·ri·o·rat·ing /dɪˈtirijəˌreɪt/ verb 1 [no obj] : to become worse as time passes
▪ The weather gradually deteriorated [=worsened] as the day went on. ▪ Her health continues to deteriorate. [=decline] ▪ efforts to save a deteriorating rain forest ▪ The disagreement deteriorated into a fight. [=the disagreement got worse and eventually became a fight] 2 [+ obj] : to make (something) worse
▪ Exposure to rain and sun will gradually deteriorate the paint.
▪ The weather gradually deteriorated [=worsened] as the day went on. ▪ Her health continues to deteriorate. [=decline] ▪ efforts to save a deteriorating rain forest ▪ The disagreement deteriorated into a fight. [=the disagreement got worse and eventually became a fight]
▪ Exposure to rain and sun will gradually deteriorate the paint.
— deteriorated adjective
▪ a deteriorated [=run-down, dilapidated] building ▪ a badly deteriorated part of the city
▪ a deteriorated [=run-down, dilapidated] building ▪ a badly deteriorated part of the city
