A term of rhetoric. A metonymy is a figure of speech in which something is referred to by something closely related to it.
Examples include referring to 'the president' as 'the White House' or 'oval office', or 'the Russian government' as 'the Kremlin'. Sometimes sayings such as "they counted heads" are considered metonymy, although using a part to represent the whole is better classified as synecdoche.
Metonymy is pronounced meh-ton-uh-mee or mih-ton-uh-mee.
Metonymy comes from the Greek metonymia, meaning 'a change of name', constructed from the words meta-, meaning 'change', and onyma (from onoma) meaning 'name'.