Synecdoche
This is a type of metonym. Specifically it’s when a smaller part of something is used to refer to the whole thing.
When we say we need “boots on the ground,” we’re talking about entire humans, not just boots. The boots are just used as a shorthand for the larger concept.
It’s pronounced “suh-neck-doh-key.”
Why I Looked It Up
From (the incredibly pretentious) Bookshops:
The book will work this way: it will embrace the comfort of orderly reading and digressions and contradictions that disturb or threaten; it will re-create possible traditions and at the same time insist it only speaks of examples, exceptions from a map and a chronology of bookshops that is is impossible to re-create, that is made up of absence and oblivion, suggests analyst and synecdoche, a collection of glittering shards and left over remnants from a history history of encyclopedia that can never be written.
And, no, I don’t understand a word of that either.
There was also a movie called Synecdoche, New York that Roger Ebert felt was one of the great movies of all time.
The film’s title is a play on Schenectady, New York, where much of the film is set, and the concept of synecdoche, wherein a part of something represents the whole or vice versa.
Postscript
Added on
In Monsters: A Fan's Dilemma, writing about Earnest Hemingway:
He became his own fame, a fame that was interwoven with his masculinity. He became a human synecdoche for the condition of literary virility.
I think this author is saying that Hemingway became an cliche or archetype of the manly, adventure writer. “Hemingway-esque” became a shorthand way of referring to the larger concept.