Synecdoche

Synecdoche (pronounced "si-NEK-duh-kee", IPA: /sɪˈnɛkdəˌki/; from Greek sinekdohi (συνεκδοχή), meaning "simultaneous understanding") is a figure of speech in which:

• a term denoting a part of something is used to refer to the whole thing (Pars pro toto), or
• a term denoting a thing (a "whole") is used to refer to part of it (Totum pro parte), or
• a term denoting a specific class of thing is used to refer to a larger, more general class, or
• a term denoting a general class of thing is used to refer to a smaller, more specific class, or
• a term denoting a material is used to refer to an object composed of that material.