The use of metonym and synecdoche are often confused. I see the city of Washington(DC) defined as either a metonym (wikipedia) or a synecdoche. Which is it and why?
Metonymy is in DC and Synecdoche is in New York?
I would say that metonymy is substitution more generally, while synecdoche is more specifically the substitution of a part for the whole. So I don’t think Washington is synecdoche, because Washington is not really part of the government, it is just closely associated with it. Whereas The Pentagon for the military is synecdoche.
A synecdoche is a particular form of metonymy. Just like antonomasia and metalepsis, which are also defined this way.
If you forget about subtileties and call those figures of speech where things are alluded to with parts of other things or as an example for other things in general all metonyms you will not be wrong. You can even call it metaphor, even though metaphor and metonym are claimed to be subtly different:
In metaphor, this substitution is based on some specific analogy between two things, whereas in metonymy the substitution is based on some understood association or contiguity.
I often feel that those differences (analogy, association, contiguity…) are overlapping and subjective, depending on the point of view and the mood of the teacher (last time I had to fight with that crap was in school, long time ago. I still remember not being convinced by the teacher’s explanations. Whoever’s fault that was)
Thanks Pardel-Lux. I’ve seen ‘hand’ snd ‘bread’ referred to as a synecdoche and metonym. Could they be either?
I`ll lend you a hand → pars pro toto, synecdoche (thus also a metonym)
She is the bread winner in the household → sure a metonym, perhaps a synecdoche, and some would see a metaphor there too.
Anything can be a synecdoche, a metonym, or a metaphor if you use it as such. The question is whether the listener will understand you in the sense that you mean. So strictly speaking I would say that neither “hand” nor “bread” are a synecdoche or a metonym per se, but they can easily be used as such. Perhaps you could compare it to a lie: anything can be a lie, it depends on the intended use of the words. A lie, of course, is not a grammatical category, but the relevant thing is that it depends on the speaker’s will to deceive. Same with your examples: it is the user’s will to have hand or bread understood in a particular way that makes a synecdoche or a metonym (or a metaphor or a comparison or an antonomasia or metalepsis… where, as I stated above, the distinctions can seem arbitrary and overlapping See → nitpicking and hair-splitting).
BTW: I am not a theoretical linguist, only a cunning practical one. Experts in ivory towers usually disagree with my interpretations and call them simplistic generalisations.
I was in agreement until the last sentence. “The Pentagon” is a tricky case. The Pentagon is a building. But when people say “The Pentagon” they are often referring to the people or organization or department that is headquartered in that building. This, it looks like to me, is metonymy but not synechdoche: the building itself is not a part of the people in it. But then, the people in it are only part of the Department of Defense or the US Military as a whole, so using “The Pentagon” to stand for the whole military is synecdoche? Maybe there are multiple layers there?
No one here in Schenectady can pronounce “synecdoche” correctly. The have no problem with “metonym.”
By the way, my favorite example of synecdoche is “Get your ass in here!”
IANA linguist, merely a language user.
Thank you for a wonderful albeit brief guided tour of all this stuff.
I have to say that it seems there were / are a lot of PhDs granted on the basis of ever finer splitting of ever finer fibers of meaning. Perhaps more lumpers should go into the field to de-complexify (is too a word! 
) it.
Turning to the OP’s question, I’m reminded that there’s a tendency in human thought to use the tree structure as the model of understanding lots of things. Which is to say there’s an overarching whole which subdivides neatly into n mutually exclusive but collectively exhaustive subcategories. Each of which divides into their own collection of differing numbers of sub categories which in turn subdivide … ad infinitum.
Damn near nothing in the natural world is that neat, and truly nothing in the world of human creation is. All boundaries are fuzzy, every category overlaps some other category at least somewhat, even the levels of distinction are not obvious or consistent, and special cases abound. And there are often totally different axes of meaning along which you can construct completely different quasi-trees of useful categorizations.
If you (any you) bring a perfect tree as your mental model of [whatever], you’ve already lost before you begin. Bring a multi-quasi-tree model and it’ll work better. Compare and contrast Linnaean taxonomy - Wikipedia and Cladistics - Wikipedia.
That would be an example of what James Thurber’s English teacher called “the container for the thing contained”:
This sounds like synecdoche rather than metonymy, but Miss Groby’s examples show she really meant metonymy. For example, when Shakespeare had Antony say in Julius Caesar : “Friends, Romans, Countrymen, lend me your ears” he was speaking figuratively of the thing the ears contained — that is, their function, their ability to listen, not some literal component. Thurber recalled that he lay awake that night trying to find an example of the reverse idea and came up with an image of an angry wife about to bash hubby over the head with a bottle of Grade A, saying “Get away from me or I’ll hit you with the milk”. That’s metonymy all right, but you can argue it’s also synecdoche, because milk is an essential component part of a bottle of milk, not just something associated with it.
Thurber also came up with an example of “the reverse idea” in the form of an old vaudeville joke:
“How did you break your foot?”
“I dropped some tomatoes on it.”
“Tomatoes?!”
“They were in a can!”
Metonym gives me a nasty rash.
Ask your doctor about Metonym.
You’re doing it wrong, you are not supposed to use it topically! Bad Burpo!
I guess I was thinking of “the military” as not just the people, but the entirety of the enterprise - people, buildings, weapons etc., which would make it synecdoche. But on reflection that’s wrong, when people talk about “The Pentagon” probably they have just the people in mind, the military brass*.
(*hah - didn’t occur to me until I wrote it)
Washington when referring to the entity where laws are made is a metonym.
Washington when referring to their football team, the Washington Generals, is a synecdoche.
It may help to remember the synecdoche song.
Washington’s football team also had a rather infamous synecdoche as its former name….
I always thought synechdoche can go both ways. Wiki agrees:
" Synecdoche is a type of metonymy; it is a figure of speech in which a term for a part of something is used to refer to the whole, or vice versa. The term is derived from Ancient Greek συνεκδοχή ‘simultaneous understanding’. Wikipedia"