Metonymy
Calling a thing by the name of something closely associated with it — the crown, the White House, the press, the bottle.
Full definition of Metonymy →:: COMPARE ::
MetonymyvsSynecdoche
The short answer
Metonymy substitutes something merely ASSOCIATED — a crown is not part of a monarch. Synecdoche substitutes a part for a whole, which are the same thing at different scales. That is the cleanest available line, and it is not universally accepted.
Side by side
| Aspect | Metonymy | Synecdoche |
|---|---|---|
| Relation | Association | Part/whole |
| Same entity | No | Yes |
| 'The crown' | This one | — |
| 'All hands' | — | This one |
What each one means
Synecdoche
Naming a thing by one of its parts, or a part by the whole — all hands on deck, wheels for a car, boots on the ground.
Full definition of Synecdoche →