Metonymy

My new favorite trope

Metonymy (pronounced /me'tɒnɪmi/) is a figure of speech used in rhetoric in which a thing or concept is not called by its own name, but by the name of something intimately associated with that thing or concept. For instance, "Washington," as the capital of the United States, could be used as a metonym for its government.

The words "metonymy" and "metonym" come from the Greek: μετωνυμία, metōnymía, "a change of name", from μετά, metá, "after, beyond" and -ωνυμία, -ōnymía, a suffix used to name figures of speech, from ὄνῠμα,
 
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