The relatedness of meaning found in polysemy is essentially based on similarity. The head of a company is similar to the head of a person on top of and controlling the body. There is another type of relationship between words, based simply on a close connection in everyday experience. That close connection can be based on a container–contents relation (bottle/water, can/juice), a whole–part relation (car/wheels, house/roof) or a representative–symbol relationship (king/crown, the President/the White House). Using one of these words to refer to the other is an example of metonymy.

It is our familiarity with metonymy that makes it possible for us to understand He drank the whole bottle, although it sounds absurd literally (i.e. he drank the liquid, not the glass object). We also accept The White House has announced … or Downing Street protested ... without being puzzled that buildings appear to be talking. We use metonymy when we talk about filling up the car, answering the door, boiling a kettle, giving someone a hand, or needing some wheels.

Many examples of metonymy are highly conventionalized and easy to interpret. However, other examples depend on an ability to infer what the speaker has in mind. The metonymy in Get your butt over here is easier to understand if you are used to male talk in the United States, The strings are too quiet if you’re familiar with orchestral music, and I prefer cable if you have a choice in how you receive television programs (in the USA). Making sense of such expressions often depends on context, background knowledge and inference.