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English definition of “ruinous”

ruinous

adjective uk   /ˈruː.ɪ.nəs/ formal us  
causing great harm and destruction: ten ruinous years of terrorismDangerous and harmful
ruinously
adverb uk   /-li/ us  
Having an accident without insurance can be ruinously expensive.Dangerous and harmful
(Definition of ruinous from the Cambridge Advanced Learners Dictionary & Thesaurus © Cambridge University Press)
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