spreading gradually or without being noticed, but causing serious harm 潜伏的;隐袭的;隐伏的 the insidious effects of polluted water supplies 供水系统污染的潜在恶果
Oxford Collocations DictionaryInsidious is used with these nouns:- threat
Word Originmid 16th cent.: from Latin insidiosus ‘cunning’, from insidiae ‘an ambush or trick’, from insidere ‘lie in wait for’, from in- ‘on’ + sedere ‘sit’.