Metonymy is a figure of speech where a word or phrase is used to refer to something closely associated with it. It's like using a "stand-in" word for the actual thing.
Here are some examples:
* "The White House announced a new policy." (The White House is a metonymy for the President and his administration.)
* "I'd like a glass of red." (Red is a metonymy for red wine.)
* "The crown will make a decision." (The crown is a metonymy for the monarch.)
Key points about metonymy:
* It's a figure of speech based on association, not similarity.
* The substitute term is closely related to the original term in some way (e.g., location, function, attribute).
* It can be used for stylistic effect, to be concise, or to evoke a specific image or emotion.