a figure of speech that consists of the use of the name of one object or concept for that of another to which it is related, or of which it is a part, as “scepter” for “sovereignty,” or “the bottle” for “strong drink,” or “count heads (or noses)” for “count people.”
Origin of metonymy
1540–50; < Late Latinmetōnymia < Greekmetōnymía change of name; see met-, -onym, -y3
1560s, from French métonymie (16c.) and directly from Late Latin metonymia, from Greek metonymia, literally "a change of name," related to metonomazein "to call by a new name; to take a new name," from meta- "change" (see meta-) + onyma, dialectal form of onoma "name" (see name (n.)). Figure in which the name of one thing is used in place of another that is suggested by or associated with it (e.g. the Kremlin for "the Russian government"). Related: Metonymic; metonymical.