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no-no

noun \ ˈnō-ˌnō \

Definition of no-no

plural no-no's or no-nos
1 : something unacceptable or forbidden
2 : no-hitter

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First Known Use of no-no

circa 1942

in the meaning defined at sense 1

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NO-NO Defined for English Language Learners

no-no

noun

Definition of no-no for English Language Learners

  • : something that people are not supposed to do because it is not proper, safe, fashionable, etc.

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