Metonymy

Metonymy ( /mɨˈtɒnɨmi/ mi-TONN-ə-mee) 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. Metonyms can be either real or fictional concepts representing other concepts real or fictional, but they must serve as an effective and widely understood second name for what they represent.