Not candid or sincere, typically by pretending to know less about something than one really does. Disingenuous behavior involves calculated innocence or false naivety.
From Latin 'ingenuus' meaning 'native, freeborn, frank' with the prefix 'dis-' meaning 'not.' Originally, 'ingenuous' meant noble and honest; 'disingenuous' is its opposite - pretending to be innocent while actually being calculating.
Break it down: 'dis-' (not) + 'ingenuous' (innocent/naive). It's like someone playing dumb when they're actually quite clever - they're being 'not-innocent' while pretending to be innocent. Think of a politician saying 'I had no idea' when they clearly did.
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