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English definition of “what's the big idea?”

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what's the big idea?

informal
used to ask someone why they have done something annoying: What's the big idea? I was watching that programme!
Translations of “what's the big idea?”
in Chinese (Traditional) 你這是甚麼意思?…
in Chinese (Simplified) 你这是什么意思?…
(Definition of what's the big idea? from the Cambridge Advanced Learners Dictionary & Thesaurus © Cambridge University Press)
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