From Longman Dictionary of Contemporary Englishdeterioratede‧te‧ri‧o‧rate /dɪˈtɪəriəreɪt $ -ˈtɪr-/ ●●○ verb [intransitive] 1 WORSEto become worse Ethel’s health has deteriorated. America’s deteriorating economyRegisterIn everyday English, people usually say get worse rather than deteriorate:Her health got worse.The situation is getting worse.2 → deteriorate into something —deterioration /dɪˌtɪərɪˈreɪʃən $ -ˌtɪr-/ noun [uncountable]THESAURUSdeteriorate to become worseAir quality is rapidly deteriorating in our cities.Living conditions here have deteriorated in the past few years.get worse to become worse. Get worse is less formal and more common than deteriorate in everyday EnglishMy eyesight seems to be getting worse.He’s never been well-behaved, but he’s getting even worse.go down to become gradually worse – used especially about the standard of somethingThe hotel’s gone down since its management changed.Nick’s teachers say that his work has gone down recently.go downhill to become much worse and be in a very bad condition, especially after a particular time or eventDuring the recession the business began to go downhill.Her health went downhill rapidly after Christmas.decline especially written to become gradually worse – used especially about standards of living, education, health etcAfter the war, the standard of living declined.Over the years, the standard of public transport has declined.degenerate formal to become worse, or to become something bad instead of something goodRelations between the two countries have degenerated.The debate degenerated into an argument between the two sides.escalate to become much worse very quickly – used especially about fighting, violence, or a bad situationFurther violence could escalate into a full-scale armed conflict.The political crisis escalated.spiral out of control to become worse in a way that cannot be controlled and is extremely serious and worryingPolice say that the violence has spiralled out of control.Scientists are worried that global warming could soon spiral out of control.Costs have been spiralling out of control. → See Verb table
Examples from the Corpus
deteriorate• My, how things have deteriorated.• Some 114 sites surveyed had improved their environmental performance while that of 30 had deteriorated.• If the dispute drags on, conditions in the city could deteriorate.• Meanwhile, prison conditions have deteriorated and the public has lost confidence in the criminal justice system.• But jitters about the deteriorating budget talks have driven yields steadily higher.• Nina's hearing had deteriorated considerably since I last saw her.• Was this not deft proof of how the human gene-pool was constantly deteriorating, how bad blood drove out good?• Air quality is rapidly deteriorating in our cities.• Strategic planning systems can of course deteriorate into meaningless exercises.• The US trade position has deteriorated over the past few years.• His condition deteriorated rapidly during the night.• Relations between the two countries have deteriorated since the agreement was signed.• It was a marriage made in heaven that seemed to deteriorate to hell in a hurry.• Ethel's health deteriorated to the point that she could no longer walk.• School buildings have deteriorated to the point where they pose a health threat to both students and teachers.From Longman Business Dictionarydeterioratede‧te‧ri‧o‧rate /dɪˈtɪəriəreɪt-ˈtɪr-/ verb [intransitive] to become worseThe economy deteriorated further in August, with orders for manufactured goods falling. —deterioration noun [countable, uncountable]a deterioration in sales→ See Verb tableOrigin deteriorate (1500-1600) Late Latin deteriorare, from Latin deterior “worse” 