Confined or imprisoned someone, usually as a wartime measure or political decision, without trial; or worked as an intern for practical experience.
From Latin 'internus' (internal, inward). The 'confine' meaning developed in the 1800s as 'intern' (noun) for prisoners, while the 'work as an intern' sense is modern from 'intern' (noun) for a trainee.
This word has two completely opposite meanings: being forcibly locked up versus voluntarily working for free to gain experience—same word, completely opposite power dynamics. It's a linguistic accident that creates confusion.
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