This most under-the-radar of tropes takes a member of a group, a part of a whole, or characteristic of a thing and makes it represent the whole shebang; the trope also works the opposite way. In rhetoric, the Belonging Trope splits into two sub-tropes: synecdoche and metonymy. Synecdoche (sin-EK-doe-kee) translates unhelpfully into “takes one thing for another.” It’s the representational trope, taking a member or part and making it stand for the whole, or vice versa. The White House is a synecdoche, a single building standing for a whole presidency.
The metonymy (met-AH-nih-mee) takes a characteristic or container and makes it represent the thing it characterizes or contains. “The bottle” for alcohol is a metonymy. But the two devices overlap so much that in the real world we can combine them into the belonging trope.
To show how the belonging trope works, I wrote a little story.