A synecdoche is a simpler symbol that captures the essence of something more complicated. For example, a family sitting at a table, each silently sending text messages is a synecdoche for the struggle to balance technology with personal interaction.
To correctly pronounce synecdoche, say "sih-NECK-duh-key." A synecdoche is a part that represents the whole. A photograph of a car that is completely covered in snow is a synecdoche for the burden everyone faces following a big winter storm. Synecdoche is a great literary device, especially for poets who strive to express a great deal in a single image.