metonym. synonym

Earlier this month, I emailed Merriam-Webster the following question. Associate Editor, Neil Serven, replied as follows.

Q: Can you help me understand the difference between these two words?

A: A metonym is a figure of speech in which something is referred to by another thing with which it is closely associated. A common example is the use of City Hall to refer to the government of a city (as in “you can’t fight City Hall”), when literally it refers to the building that houses a city’s government offices.

Typically, synonym refers to a word that can stand in for another word and retain the same meaning, such as lukewarm for tepid, or avarice for greed, or java for coffee.

In extended use, however, synonym is something used when metonym is meant, as when one says, “Peoria has become a synonym for Middle America.”