insidious Meaning in the Cambridge English Dictionary Cambridge dictionaries logo

Meaning of “insidious” in the English Dictionary

"insidious" in British English

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insidiousadjective

uk   us   /ɪnˈsɪd.i.əs/
insidiously
adverb uk   us   /-li/
The ​diseasebegins insidiously and ​progressesrelentlessly.
insidiousness
noun [U] uk   us   /-nəs/
We must ​recognise the insidiousness of these ​racialstereotypes.
(Definition of insidious from the Cambridge Advanced Learner’s Dictionary & Thesaurus © Cambridge University Press)

"insidious" in American English

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insidiousadjective

 us   /ɪnˈsɪd·i·əs/
(of something ​unpleasant or ​dangerous) ​gradually and ​secretly causing ​harm: Cancer is an insidious ​disease.
insidiously
adverb  us   /ɪnˈsɪd·i·əs·li/
His ​negativeattitudeslowly and insidiously ​spoiled the ​atmosphere around the ​office.
(Definition of insidious from the Cambridge Academic Content Dictionary © Cambridge University Press)
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“insidious” in British English

“insidious” in American English

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