I keep getting page hits from people who typed “metonymy” (and maybe “poetry”) into a search engine. I’d hate for those people to have to go away empty-handed, so here’s the definition you were probably looking for.
Metonymy is a rhetorical figure where something contiguous with a thing is substituted for the thing itself. It is often confused with synechdoche, the substitution of part for whole, which is not surprising: I’ve never quite manage to unconfuse them myself. The linguist Roman Jakobson suggested that metaphor and metonymy form two poles of figurative language use, and that whole genres of literary and popular culture could by characterized by the accent they placed on either metaphor or metonymy. This is probably a load of cobblers, but it makes for a good theoretical parlour game (see Lacan, passim).
If you did come via a search engine, you’ve probably already seen the wikipedia entry.
The poem titled
Half Cocks: Metonymy on this site was written at a time when news stories about a pregnant teenager strangled and left dead in a churchyard were running in the same papers as stories about the tsunami in South-East Asia. I couldn’t write about the masses killed by the tsunami, so I wrote about that small, singular disaster instead. Some of the language of the poem hints at a larger picture (e.g.
population graph), but the closing image is metonymic/synechdochic: it focuses on the substitution of a contiguous part of a person - their
remains - for the whole (the reference to Alice Sebold’s The Lovely Bones is intentional, although incidental).